I’m a bit stuck
My 1988 volvo 740 won’t crank over

Battery and connections ok
Power fed to green starter motor trigger wire does crank starter so starter is ok
Tested key switch by exchanging it with a spare
Tested park neutral safety switch -ok

When key is turned to crank ,
headlights dim and I hear a slight click from relay tray swapped relay marked J

Tried following Haines manual, for 87 and newer
It indicates power fed from key pin 50 through park switch to starter

I checked each wire at starter switch there is not one tgat is hot when key is turned to crank position tgat us not hot in other key positions

Found Volvo schematic , it seems to indicate much differently
Oh jetronic B230F starts on page 8 ( I’ll post link after )

It shows a test plug and wiring ( page 8)
9 is the starter motor wire at starter is BL- GN

To “p” - connector , electrical distribution unit seems to show a small jumper ,

To “B” - Connector left A post - pin 24

Through pink wire

To “A” - connector right A post - pin 15

To ECU pin 30
—————————————————-

So the Haines schematic seems completely wrong
and the starter is not fed from key but fed from the ECU

The difference in the two schematics totally confused my efforts to understand the path of the starters trigger wire

I’d like to identify this test port for the starter , I thought it may exist to aid in cranking to check compression etc by a mechanic or to verify the 12v to starter upon cranking

Am I on the right path ?

I can imagine a lot of people got caught with no crank issues due to the Haines manual’s 740 1987 and later schematic indicating the key as being the source of power to crank the starter

I am assuming the Volvo schematic that
I have which dates about a year after my car to be correct

Thanks for any info you guys can offer


Phil

A) Your 1988 B230F is LH 2.2. The pages you were looking at in the Volvo wiring manual that Bill Garland copied are for LH 2.4. In 1989, the turbo was still LH 2.2, so go up a couple of pages for the B230FT wiring which will be similar to your year.

B) The ECU has no control over the starter motor and has no idea whether or not it's even cranking. In the Volvo wiring diagram manual, the Starting Circuit diagram is on different pages. Bill's site only has the ECU and ignition pages. The full 1989 green manual (not 1988) can be found online with a bit of effort. I recall there's one in the technical archives at https://ozvolvo.org/archive/

C) You've pretty much proven it's not the starter or solenoid by being able to apply 12 volts directly to the starter and get it to crank.

D) The initial suspect should be a worn ignition switch. Often times a worn ignition switch becomes intermittent and rocking it back and forth or pushing/pulling the key while turning it will get it to crank until it's completely worn out and gone. If it's not intermittent then you can do exactly as Bill said. If you apply 12 volts to that purple wire spade connector with the ignition switch on in KP-II and the engine now cranks then it's the ignition switch and/or battery connection (hence why Bill said to check the battery connection first).

Another and often easier way to diagnose the starter circuit is using a multimeter at that purple spade connector. With the other test lead on chasssis ground, when the ignition is turned to the KP-III start position, you should momentarily see 12V otherwise the ignition switch is gone and/or battery connection.

E) If it's not the ignition switch then the next most likely candidate is the start inhibit (PNP) switch on the shifter console. As a quick check of that switch, try starting the car in both Park and Neutral to see if it's just one side of the switch that's gone. Also try pushing the lever all the way forward in Park while trying to crank. To properly test the start inhibit switch, with the ignition off and again with your meter still on the spade connector, use the ohmmeter function with the other test lead on the blue-green starter solenoid wire. In both Park and Neutral you should have continuity, but not other gears. The PNP switches are a bit of a pain to get at and remove without breaking the plastic studs, so work the circlips off very carefully. Once safely off, you can often restore them by prying them open and cleaning up the copper contacts, otherwise they need to be replaced. They're supposed to be lightly lubed, such as with dielectric silicone grease or even vaseline. You can temporarily bypass the PNP switch by running a wire from the test connector to the blue-green wire terminal on the starter.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Thank you Dave

You are right it’s 2.2 not 2.4 and I might still be off on the wrong schematic

I did not find this purple or blue wire seevice port

I did take apart and swapped the park neutral switch , I replaced it just before this issue,
because it had broken when something fell in the valley and I moved the shifter but it tests ok Open circuit unless in park or neutral then coded circuit .

I didn’t see any intermittent issues with key switch or my spare key switch

I figured I’d find a wire at key that is hot only when key turned , and did not
Maybe that’s normal ?

I think maybe our posts crossed , as I hit post then saw you replied

Might be a corroded 8 pin plug in engine bay DS inner fender , near mass meter

Appreciate the detailed help !

Phil

Hi Phil,

That remote starter connector (a purple wire in 1989) normally lives buried in amongst the wiring harness part way along the left (driver side) fender. Have another look for it.

If it's a bad/broken wire somewhere and you've previously been working in the tunnel console area on the PNP switch then probably worth the effort to pull that area apart again to see if you can spot the damage or a broken wire on the PNP switch. Once you've got access to the PNP connector you can do some more testing and attempt to bridge it there, same as if you had access to that remote starter connector.

Good luck
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

It might be as early as 87
It’s registered as an 87 but thought it was 88 model year

Mine has the distributor at the back with a hall sensor
Later models had the crankshaft position sensor

I know some stuff about the differences because I also have an 89 Volvo and 89 740 , they have the code reader
LED light box and a different ICU same ECU I think

Anyway the wagon with the no start problem is the hall sensor ,earlier type

I’ll keep looking for the plug but I’m not seeing it ,


Phil

Hi Phil,

The 89 manual shows the service port where Dave says in the engine bay harness
high up the drivers side fender about half way from the battery to the firewall.
It is a short wire with a single plastic connector shell for a 1/4" spade.
I have fuzzy recollection that one of my Volvo's had that port breakout on the
passenger side also up high. (look on the passenger side too)

You can try plan B as follows: Put the key in run position and tranny in Park.
Start by shorting the two fat solenoid lugs with a big screwdriver.
I had to do this with two intermit no start starter motors in my 740.
They would work fine then suddenly be dead as a mackeral, then spin the starter
with the screwdriver and back in business for months or minutes depending on
Murphy's mood. There's an AWD post now that someone found this problem was due to a binding solenoid, and I'm hoping to hear more details from him.
I still have one of the funky starters so I'll take a look at the solenoid when
I get some time.

You did clean ALL the battery terminals? Yes?

Good luck, Bill

when I initially went into this problem it was starting, but I had noted that it wouldn't start in park, only neutral, then I realized the park-neutral switch was damaged so I swapped it and in doing so cleaned the contacts and greased them with a dab of electrical grease.

now it would stand to reason that's the area where things got messed up but it could be that the intermittent was not related and it's somewhere else and still haunting me.


I made a typo when describing my PNP switch above..

"I did take apart and swapped the park neutral switch , I replaced it just before this issue,
because it had broken when something fell in the valley and I moved the shifter but it tests ok Open circuit unless in park or neutral then coded circuit ."

- I meant to say I have continuity from key to park /neutral switch and back to the key, I unplugged the keyswitch and verified that i do have continuity(back to key) in park or neutral and no continuity if the shifter is in other positions. Im not suspecting the PN-switch to be the issue.

i checked all the fuses and I'll check them again. I did not pull the fuse tray. I did find that the solenod J had a bad contact, I pulled it and swapped it. and sprayed some cleaner down in the socket. it was clicking when I pressed on the top of it but that cleaning and swapped relay seemed to stop that from happening. both relays had a J on them.

pulling the console is always such a PITA , I think I was trying to take the screws out from inside that hold the side panels and really I may be able to pull both sides that surround the fuse tray as one piece. getting the radio out and a replacement in took a lot of disassembly in the area. I had a hard time releasing the radio.

if necessary I can pull that all back apart to inspect under the fuse tray. I do have the spare fuse tray, still connected to my spare harness for comparison.


maybe this service port is on the passenger side? I'm at work now but will check and also verify if I can see it on my 89 240 0r 89 740. If I can confirm what you mention on the other cars then I can look and verify if it's not there It may be in a different location, or may not be present on my model.

as noted the car with the issue is a bit earlier , using hall sensor in distributor whereas the later ones, in my other 2 cars used the TDC sensor instead, that might help verify when I'm on the right wiring diagram. that schematic I initially posted was for a newer 2.4 litre and that is wrong.

I do have the correct blue book parts book so it might show some details of the wiring harness. I can look into that.


the replacement PN-switch did have a different plug on the PN- switch wires so I soldered and spliced on the older connector but the wire colors were the same. funny I did note the backup lights weren't on, but I think that may be unrelated. its basically two switches and I verified the reverse one makes contact when in reverse. I don't think I confused the wiring between the two switches during my plug splicing.

since I'm a bit confused I figured I should remove my spare engine harness from that old engine and have a closer look at that one. I noted the 8 pin connector looked a bit dirty on both the spare harness and mine wouldn't separate easily. . If its in a sorry state I could replace it with a terminal block if I splice in a bit more wire length to do that. I'm ok doing a reliable solder heat-shrink and splice job.

I think I should find continuity back from that starter trigger wire, I think it's green with a blue stripe. I think it should go to the 8 pin plug and once I'm sure I'm on the right pin then I can follow that through my spare harness, I want to see if that wire terminates at the key switch, or where it does go (reverse engineering) if the triggger wire for the starter eventually terminates at the key then I must have power there..

I stuck a pin throgh each wire connected to the key, and tried all the positions on each wire and wrote out a little table for myself. the actual keyswitch plugs into the end of the harness at the key switch so I can swap key switches and I'm just turning it with a screwdriver so I have access to the wiring. the problem is not with the mechanics of the key, that's not electrical. I can unplug the keyswitch and access the ends of the harness wires there and there is some numbers to ID the wires on that connector.



right now I have that key switch poking out from under my speedo and the speedo reconnected.

I should be able to ohm out using the beep function on my meter and check if with key turned ( or switch removed) that I have continuity from the key lug to that 8 pin plug and then on to the green wire on the starter.

I know there is other wiring involved because when I turn the key this relay in the tray ( J) clicks, that seems to also indicate that there is some switching going on as I turn the key to start.

there is some circuitry that turns off the headlights during cranking. maybe that's what the J relay is doing.. this means the circuit is more complex than simply the key feeding power to the starter motor trigger.

if there is a relay that turns the lights off during cranking, then maybe it also has a contact involving this crank circuit?

Easily to become totally confused, and frustration and brain seize then sets in, so I need to break this into baby steps of troubleshooting. I though maybe verifying my way through from the starter back up into wherever it originates might help me understand why power isn't being fed to the starter trigger.. I think I might end up at the key if I follow it back but maybe some relay terminal is involved in the electrical path.. the wire loom isn't confusing, it could have a break but shouldn't be too complicated.. that's just a bunch of wire.

the key switch and its various functions such as dimming lights during cranking are very confusing.

It may or may not be normal that I have no wire at the key that is hot only when the key is in position 3 (cranking)

Phil

Phil, you just said "I have no wire at the key that is hot only when the key is in position 3 (cranking)"

There's your problem. Pin 50 on the back of the ignition switch (the pink wire) is supposed to be hot when the ignition switch is in KP-III for cranking. The other end of the pink wire is at the PNP start inhibit switch, so if that was easier to get to then you could have looked for voltage there. Of the few ignition switches I've needed to replace, it was pin 50 that was the problem, likely from all the accumulated arcing that goes on every time you attempt a start.

BTW, nothing in the start circuit that's involved with cranking involves the relay tray and fuse panel, so no worries about having to remove the radio and center console side panel. After you've done it a few dozen times, removing the panels is now automatic for me. You can more easily take the side panels off the tunnel for limited access to the PNP switch and its connector for testing.

Also, there is no special headlight cutout circuit during cranking. It's all done by the ignition switch. In KP-II, pins X, 15R, 15I and S have power, while in KP-III only pins 15R, 50 and S have power. Pins X and 15I run the unneeded high load circuits like headlights that are switched off during cranking. This can all be found in the green manual.

As an added reference for your car, the Volvo master wiring diagram for the 1987-on 740s that's used by Haynes in their 740 manual can be found here https://www.v8volvo.se/mekartips/volvo/Filer%20740/Volvo%20740-760%201987-1987%20Haynes.pdf It should be reasonably accurate and match the green manual. The starter circuit is at D-3, showing the pink wire off ignition switch pin 50 to the PNP switch 71 and then to the starter motor as the blue-green wire. The dashed lines at the PNP switch indicate that a jumper is used there instead for a manual transmission. 212 is the remote starter connector under the hood (I mistakenly said P is a purple wire, it's pink -Volvo calls purple VO for violet). The dashed lines for 130 in the diagram are for the glow plug in diesels and 293 is a connection for the idle valve relay used in the B200K CI K-Jet engines that may still have been present in Europe. Neither of those appear in the 1989 green manual.

--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Thanks very much dave
What you said all makes sense there
Some took a bit to settle in

The Haines book I have in hard copy
I figured it was all wrong but I think it was just
that I was failing to interpret it properly
and when I saw that 2.4 litre being fed by the ECU
I got on the wrong path altogether

I think you both steered me right
It’s not fed by the ECU , that’s wrong
it’s fed by the key switch

Thanks to both of you for your help
I’ll get this yet !
Phil

Hi Phil,

Delivery to the following recipients failed permanently:

* philmillwright@yahoo.com

Reason: Permanent Error

Can't send you files with a bogus address.
Don't you have a dataminer free email address?
Most ISP's will give you ten ?
Use them and eventually you can join the class action suit when your ISP
gets caught selling your email files to Goggle.
The lawyers will get richer and you'll get the "usual".

Bill

Bill im so sorry
It wasn’t intentional but I mistakenly said
Philmillwright@yshoo
I should have put
Philmillwright@
Gmail.Com

That’s why it failed and it was caused by my error
I’ll go into the preferences and see if I can change it in the forum if it’s wrong in there
That was my mistake. Sorry for causing the unnecessary confusion

I have an email @ yahoo that I just use for spam and just wasn’t thinking straight

Last night I probed the spare harness from the engine bay plug ,
it has a green wire with blue stripe , that’s the plot at the starter
It changes to blue along the way , through a big master plug

It ended up NOT going to the key but to a black 4 prong plug.
That plug shares two pink , a blue with red and a blue , maybe another wire
It’s a black 4 prong plug that is offset
Like a rectangle sliced in half and shifted horizontally .

Those colours are used for the park neutral switch so I might be getting warm


It’s close in the harness to a small bulb and the plug for the Park- neutral switch
I’ll check in the car , maybe I just simply have that plug disconnected
I’ll verify once I can and get back

Phil

Hey Phil,

Now you can get mail, congratulations...except it's still a Chzyit dataminer.
As Mr. Creosote said: "I need another bucket!"

Maybe you'll plug that connector in and solve the problem?
Then you can go directly to Miller time and collect 200 dollars.

Cheers, Bill

So as suspected it was completely my fault ;-)

I had switched the park-neutral shifter safety switch, since I had one on hand and it was not starting in neutral, it had also gotten a little broken when a screw dropped down in the valley of the shifter, wasn't noticed, and got stuck in there.
my replacement was identical but the 4 prong plug was different, so no problem I cut the plug off and used my old one, did a nice splice job.

well finally I found that I had a blue and a red there at the connection and had them accidentally transposed which wasn't obvious, the two almost looked the same as they are preominantly blue..

so no schematic made sense, I didn't have a bad part to find so each part seemed ok because it was. of the different mathematics of course none made sense, I had no power at the key when it was on..

I followed my old harness from the engine plug, checked continuity and it ended up near that plug.. Of course once I found my mistake it fired right up.

now its a happy friday ! i can just put it back together. I found a coule of little sots where the wiring needs some attention. the wire to the starter missing some insulation. the engine harness plug needs cleaning up, but wasn;t the issue..

I realized when reaching down near the starter, Id left he key on and theidle air control valve was vibrating..
I think maybe the coil in it has an electromanet and it's maybe worn a bit loose in it's bore and probably just needs replacing, or something..
I'll switch that out and see if my other old ones do that. it can probably be tested out of the car... maybe I can clean it too.

I recently cleaned the flame trap. I had another car the same and that one plugged at the flame trap and it was pushing out the dipstick and spewing oil but it's just a plastic screen thing so I cleaned it up. I caught it before it blew out the oil seals.
I found a molded hose just below it, its about 3 inches long and you can't really see well in there. it was hard as a rock and full of holes. it was very cheap on rockauto..

Thanks so much, especially to Bill and Dave who put a lot of effort into helping me through all this ..

Thanks very much dave
What you said all makes sense there
Some took a bit to settle in

The Haines book I have in hard copy
I figured it was all wrong but I think it was just
that I was failing to interpret it properly
and when I saw that 2.4 litre being fed by the ECU
I got on the wrong path altogether

I think you both steered me right
It’s not fed by the ECU , that’s wrong
it’s fed by the key switch

Thanks to both of you for your help
I’ll get this yet !
Phil

Hi Phil,

First you should ditch Haynes and find the Volvo wiring Diagram for your model year. The 1989 book is TP31383/1 Dunno the number for the other years.
Hunt your book down (PDF) online, or hard copy at Ebay. They come and go.
Hard copy is the best.

The ignition switch pin 50 (Pink) does supply the +12V to the starter solenoid
via Pin 4 of the start inhibitor switch connector then pin 3 (Blue Green) to the solenoid.

You just need to confirm with your ohmmeter that the switch is closed when in park position and open in other positions.

If the inhibit switch is not closed in park, it wont start.

Bill

I found this schematic on that OZ site. its a bit later and some is in swedish but it seems to show similar to what found initially in Hanes, it does look like the key should have a hot wire to the starter, and it should go through the park/neutral switch on its way.

I can't seem to post a link but if you go here:

https://ozvolvo.org/archive/

then search for "740 -89" then it comes up..

this is a bit fuzzy and some is Swedish and this schematic is a year or two newer than my car but it does indicate the same wiring layout basically. there is a bit of additional , sort of greyed out detail, that is hard to read but maybe that's for a diesel model.

Since I could not detect a wire that is hot with key turned to pos# 3 (crank) I must have something wrong there. You both seem to think it should be like that and feeding the starter via the park neutral switch which cuts power to starter when it is not in park or neutral.

I could open the key switch and see if I can clean it but I have two there, they are easy to swap, I could get another from a standby car..

I can't imagine what may be mixed up. no intentional changes were made.

there is a splice to the "blue with red" that was added near the key,
that could be non original , it was soldered and wrapped up in there and the way it was taped seemed like it hadn't been undone so I figured maybe some factory mod.. It had been taped with a cloth tape which had turned all sticky , no heat shrink but I dont see how one could put heat shrink over because the wire is crimped into the switch socket and this splice was near that socket.


that added wire is the same size as the other two red wires ( big ones) that feed the key from battery, I'm not sure where that runs. obviously it worked before and had not been added anytime recently. I initially figured maybe it was to run a radio and had been added , or similar.

I bought the car some 12 years ago with stock radio and tapedeck, just changed it for the same one, because it was going crackly, bad solder joint probably. it had 88K now about 160 K The car or the radio hadn't been messed with that I could tell. no added options. no alarm or anything additional.


I do have 12 V at the two big red wires , so the key has a power feed. there is a big black wire at the key, not sure why, it is not grounded. there is a yellow and that's so the alarm can "ping" if I leave the key in.. it works if I depress the key.

I probably just need to get in there with my meter and try to figure out why that wire at the key is not hot when the key is in the crank position pin (50 the pink), it should be hot with key turned, it is not, so I need to find out why and put other ideas aside.


if all is right , I should be able to ohm between that key wire and the trigger blue with green stripe , at the starter and get continuity. if I do my issues are not in that engine harness plug. If I dont get continuity there I will open that plug , Id like to clean it anyway.

pretty sure I could rig a button up to start the car and still use the park neutral switch, bit mickey mouse I know.. I doubt both switches I have are bad with the same issue.. I can usually just check any switch with a meter but the keyswitch is a little complicated, it probably has a few wafers or sections in there, or similar complexity.

I'm tempted to try to pop the key-switch open , see if I can clean it.. the idea also came that I might drill a small hole to wash inside with deoxit and not disassemble it to see springs and stuff take flight. fill it and dump it a few times, maybe add some electrical grease?

I think if its not bad dont fix it, I need to diagnose it, not come up with some funny-fix to avoid confusion. its going to be one issue not 10 issues and I dont need to create any more before I find the cause. I'll recheck the key-switch , and the neutral park switch.. its likely I inadvertently created the issue and less likely some gremlin just crept in under my hood.

Hi Phil,

First, Brickboard is really gagging and thoroughly Googlified with lots of
delays for hacking your O/S, and crap ads. Many features busted.
Jarrod must be long gone with his last copyright signature 0f 2022.

Ahoy Dave, Do you have any news about that?

I tried to send you the starter schematic to to your philmillwright at Y..com
with no luck. bad address, try again.

Please read the posts and come back with answers.

Bill

Hi Bill,

Yes, the brickboard seems to be on some kind of end of life support in recent months. The server is crawling as bad as the days it was on Jarrod's old IBM 386 PC (or whatever spare PC he had access to at the time). That's why all the duplicate posts these days with people hitting Submit a second time or backing up and re-posting, which simply wastes more precious bandwidth. I've seen no feedback from Jarrod in ages. Last I heard, Jarrod was still running it on his own home server. I'm not an expert on such things, but recent changes suggest that it's being throttled by overall bandwidth restrictions (as determined by the host server account) coupled with an excess of Google ads having to be included in the process from the Google ad servers. Doesn't seem to make much difference with or without an ad blocker. It may also be that Jarrod somehow has it throttled down on his own internet connection. Can't blame him for ignoring us or cutting corners while doing his best to keep this going for such a small user base and no worthwhile revenue to offset his costs, let alone his time.

Also, the brickboard cookie handler is forever getting out of whack with your current browser cookies (at least three different brosers of mine have periodic problems) which causes a server error, denying further access until the cookies are either manually cleared (an instant fix) or the cookies eventually time out (like the next day).

Based on time of day, there's seemingly no relation to the number of simultaneous users (as few as there are now). Every now and then I get a fast normal page display, like quite a few this morning, but 95% of the time it's more like 10-25 seconds to refresh or display a page, which is an eternity for most people these days. Back in my very early IT days as a mainfame and minicomputer systems and communications analyst that would have been almost acceptable.

A simple single packet ping I just did to the server was variously from 1 to 300 msecs from various parts of the planet, with USA pings being among the worst, averaging over 150 msecs. That strikes me as pretty pitiful to turn around the many packets and ads needed to display a full webpage.

It would be a crime to lose the brain trust in these forums. Between the two main forums, there's probably well over a 1,000 years of accumulated Volvo knowledge and experience here. The average contributor age in the RWD forums is likely well over 65 now, if not closer to 75. Of course the average age of our RWD cars is in the 30 to 40 year range, so little surprise the owner base is also aging. A number of us are no longer fit to regularly crawl under a car. Even I'm considering farming out jobs to a shop with a hoist, like installing the engine mounts and exhaust systems that are currently on my do-list.

Cheers to all of us still here, able to help and learn from others to keep so much of this aging Swedish iron still rolling!
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

About the Foum here

I once , 20 years ago started a forum for the Canadian vintage radio society
I got server space and launched a PHPbb forum
It’s free software and the costs were maybe 100 or something for the server space plus the domain name has some yearly cost something like 40 bucks maybe , not hundreds

I really struggled and it took time but mostly because I didn’t know what I was doing
I used akwayswebhosting which is in Texas it was just an arrangement I took over

I struggled to get enough traffic and I’d go to the club meetings and a lot of those old guys were not very computer Savy and couldn’t get much input or encourage them to use it

I did get a few members making posts and it showed promise some were too distant to go to local meets

It eventually got decided for me that the forum should be for paid members only and I didn’t think that would work because I struggled to get the post count up as a free forum I wanted to use the free forum to help draw in new members and to include distant members better

Eventually the group decided they wanted to hire a pro website developer so I passed the duties on and it might still survive , they tried to run it in some other software and it went dead slow and I basically washed my hands if it the club had some disconnects and tge politics I’ll leave out

The VCBC Volvo club of has a good core group of leaders , And a couple hundred ir so members
I wonder if someone could unite this forum with VCBC
or if someone might want to be involved in that
It would be a shame to see it go

Lots if forums run on PHPbb
When I ran it I had a lot if sign ins that beat the captcha mostly from Russia or Italy
I had to monitor the sign ins and manually let the real people in and not allow the spammers ( machines)

it was a bit of a chore and it probably needed some security updates ani being not too savvy it was a bit daunting
But that software works well, full of good features and I think if someone who knows what they are doing it’s possible to start one without it being a huge cost

I think the VCBC could really benefit from having an associated forum but I’m not sure if the leaders want to take all that on or who might , or if those involved in running this forum have really lost interest or what ?

I got into that “Mathiew’s forum” before I came here with this particular volvo problem , most were into newer cars and someone suggested I try here because there was little action on the older cars

If the forum is managed privately it can eliminate most ads and new users just naturally know how to use all the functions in a PhpBB forum

If this is moved , then it would help if the current owner could help by using this domain name and redirecting … then it would be possible to redirect members to a new forum so that returning members didn’t get lost , they would need to resubscribe and I don’t think I’d know how to import old posts so lots might be lost

This one runs on some pretty basic principles like Craigslist , the simplicity is cool but I have no idea how to post files or pictures , there might be pretty limited server space on the computer it’s running on

Probably most including me can’t see spending a lot of time at it but it’s possible I’m willing to contribute in some small way but wouldn’t care to own the responsibility

I’m in no way suggesting it should be “ taken over” just that rather than see it die a slow death , if the current owner wanted a break from it
maybe what’s going already could be transferred to someone with interest in maintaining a forum on some actual server space
I think a lot of old Volvo lovers would still like to have a forum that works well and I think a web forum would be a great asset to the VCBC
A lot of us have parts collections and interest in them still
I had to wonder if maybe there could be some coordinated plan plan to keep it going ?

Setting up a forum isn’t all that hard or super expensive for someone savvy
Getting the post count up is harder as the webmaster can’t make all the posts so lots of forums fail due to inactivity .

Phil

Yes I’ve noticed it’s slow
philmillwright@ yahoo Dot com should work ok
No spaces , two L’s in millwright
Probably a typo

it goes to my phone so I’ll see it too and it’s fine to send any files there I’ll print them at work.


I was confused that the lights could dim in the crank position
and figured ( incorrectly ) that it was triggered by the same start trigger wire, but

I think that function may be working by way of one of the other contacts being interrupted when key moves to start , and not triggered or involved by way of pink wire , starter trigger.

maybe this is what the big black wire is for as it’s a heavy amp circuit
Lights go out with key off too , probably same wiring and unrelated to cranking circuit



I initially had the line of thought it uses a relay for that . And couldn’t ascertain why that still works

I realized it’s probably that the lights are simply fed off the key switch on a separate terminal

I was on the thought pattern that a relay is involved for light switching but I don’t think that’s the case.

Hi Phil,

You can try putting the ignition key in KP2 (run position) and
make a jumper to put +12V from the battery to the service port.
Use a 1/4" male spade lug to the port that breaks out of the harness
on the drivers side with a single pink wire.

If it starts then your ignition switch is the culprit with pin 50 dead.

Before you condemn the switch, go back to your positive terminal on the battery
and the piggy backed wires.
Examine the terminal ends and look for telltale Greenish blue copper oxide
indicating ratty terminal ends at the crimp. Shine up everything and reassemble with conductive grease. Nickel or copper anti seize or Penetrox.
Wire brush the battery anodes for good luck and use the same grease.

Post back with your findings, Bill

I had a look and can’t find the pink wire
service port that you mentioned
Near the round firewall plug in the engine bay
There is only a wire to the brake line connector
A couple of wires or hoses up to the hood

The design incorporates an engine harness
and it plugs into the main harness
at an 8 pin connector
There is an unused 2 wire connector coming out there,
some unused option maybe.

I have a complete harness I pulled from same year sedan
With the same options so I have it laid out
on the floor I’m not seeing differences
Yes I removed a whole harness,
pretty well intact :)


The engine harness is still strapped
to the engine which is nearby
I tried following the starter trigger wire
on that engine to the plug to check continuity
and found none tgat part is a bit hardened

I’ll remove that harness from the engine
to study it or copy it if I need to
It hugs the block so susceptible to heat oil etc



I think I should check if I have 12 V at that 8 pin engine
harness connector on my own car when key is turned

I should check continuity ,
through the engine harness
to the green and blue wire
that triggers the starter.

I can feed the starter from that connector break
to test that section of wire

That 8 pin connector is stuck
, probably corroded and pouring rain out
no garage gave up for the moment. I’ll soak it in cleaner
and try that again tomorrow
that could be the problem area ?

The Volvo schematic I have shows that
wire connects to the ECU
NOT THE KEY!

I did find Hanes and I think Bentley of near
the same years where
the schematic shows that the key switch
feeds the Starter motor , like older cars always did

Since I didn’t find the service port,
and suspect the wire goes to the ECU , I thought
I better not try back feeding anything
might blow the ECU if I’m on the wrong wire or misinterpreting

I checked at the key :
Removed speedometer
Removed 2 screws holding the
ignition switch to the key and pulled the key switch out
Reconnected Speedo wiring

Now I can access the key switch

It unplugs so I tried a different key switch
I can turn it with a screwdriver.

NONE of the contacts at the key switch
are hot with key turned to start ( pos 3)

- this I found surprising, and later
when I discovered that it looks like
there was a wiring change - to the ECU feeding
The starter , not the key ,
I began to figure my schematic is wrong

This is why I want to study my spare
harness to confirm if it runs to ECU

The park - neutral switch on shifter
has continuity when in neutral or park

Those wires run to key terminal
and both showed continuity,
only when in park of neutral

There are two thick red wires ,
fed by the battery to key and
they show 12v no voltage drop
but granted that’s without a load
Still I’m not suspecting bad
battery connections, but possible

I can clean battery terminals and
yes those “extra wires” there on the pos side again
but I don’t see or measure a disconnect there

The engine and starter body are grounded.
12 v to starter terminal DOES make it crank
Problem is not the starter

That’s where I’m at , I’ll continue this as I’m able
Work M-F but I’ll keep at this evenings etc
until I can figure it out

I think I have any spare parts needed.

My spare key switch could have the exact
same issue but it worked before I disassembled that car and was kept dry
I think that probability is low , but possible that they are both bad

I’m suspecting a rotten wire in engine bay side
maybe corrosion got in that 8 pin connector.

Fixing it will be the easy part ,
I suspect .Finding it is probably harder.

I truly appreciate the help !
Phil

Here is the Volvo schematic refer to page 7 and a few pages after

this ;

Page 7 of https://www.nuceng.ca/bill/volvo/Volvo740wiring.pdf

LH-Jetronic , B230F

Page 8

Call-out 9 is the starter motor

Wire at starter is BL-GN

To “P” - connector, electrical distribution unit” It depicts a jumper, or similar

To “B” - “Connector , left A post “
pin 24

Through pink wire

To “A” - “ Connectir , right A post”
Pin 15

Through pink wire

To ECU , pin 30

Here is the Volvo schematic refer to page 7 and a few pages after

this ;

Page 7 of https://www.nuceng.ca/bill/volvo/Volvo740wiring.pdf

LH-Jetronic , B230F

Page 8

Call-out 9 is the starter motor

Wire at starter is BL-GN

To “P” - connector, electrical distribution unit” It depicts a jumper, or similar

To “B” - “Connector , left A post “
pin 24

Through pink wire

To “A” - “ Connectir , right A post”
Pin 15

Through pink wire

To ECU , pin 30