My latest issue is that the Speedo seems to swing wildly and then stops working all together, and neither does the Odometer. Does this sound like a
wiring/ground problem from the Sender or the Speedo cluster?
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-Cool Volvo- 1982 240 4 Spd OD w/ 248K, 1989 240 5 Spd w/ 241K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Can anyone tell me if the single wire to connect from the harness to the Lower Left Rear of the instrument panel, is Red/Yellow or Red/White.
Thanks for your quick response.
--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Well, it seems that I celebrated too soon.
When I first get going, the speedo works fine,
but after a short while I start getting wild swings and then it stops working.

Art... you suggested to check the "silicone-insulated flex cable between the sender on the differential and the car body grommet". When I was under the car, I noticed that the cable snakes over the top of the gas tank.
Can you provide a suggestion of where I can access the grommet.
Can I get to it thru the trunk in the access hole to the fuel level sender?
--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Art, can you suggest how to access the car body grommet of the flex cable.
Thanks for you help.
--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Thanks guys. It was the Red/Yellow plug as you both suggested.
After reconnecting the panel, the speedo seems to be working fine.
There were a couple of small swings, but hopefully the L-plug was
just getting "seated".
As usual, it's the simple solutions that should be tried first.

--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Red Yellow goes in the lower right corner looking from the front of the panel.

Like Art already said, keep that red white away from the rest of it. It makes things it gets plugged into go boom, except for the Tach.

Regards,

Paul

Hi there,

The red/white wire is definitely the tach wire. Don't put it anywhere but on a tachometer. The red/yellow is for the overdrive light. The way I remember it, the connector is smaller (3/16") and fits on the small tab in the lower right corner.

The likely cause of an intermittent speedometer is at the rear of the car in the silicone-insulated flex cable between the sender on the differential and the car body grommet. It also could be a loose "L" connector on the cluster (speedometer) itself, but I think you would be able to see some action if you rapped on the dash as you were driving steady down a smooth road.

The intermittents are the hardest to find.

--
Art Benstein near Baltimore

Can I get to it thru the trunk in the access hole to the fuel level sender?

Trunk means sedan, right? In my 89 sedan, the speedo sender cable (gray) shares the grommet with the fuel level sender cable (black), coming through the fuel tank access plate under the trunk carpet. The junction box for the speedo sender cable is under a plastic pop-off cover just to the left. In one of the later cars, the cable gets its very own grommet.

I don't know how you will test it, but I would disconnect it inside the little black anti-tamper box, securely clip an ohmmeter to the leads and begin wiggling along its length to the sender itself. It could be tricky without a helper or "audible" ohmmeter.

(oops replied to myself - well you'll find it)


--
Art Benstein near Baltimore

If money doesn't grow on trees, then why do banks have branches?

So, I checked the gray sender cable coming thru the grommet and played with the connections. What is really bizarre is that when I first get going the speedo works fine. After about 5 minutes, it starts swinging wildly and soon after just stops altogether... EXCEPT: when I go over a bump and then I get a temporary reading on the speedo. Could it be the Sender itself, that works only when it's cold?
--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Thanks Art.
I will try poking around.
I really believe it's some type of loose connection,
because every time I go over a large bump, the Speedo registers.
--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

I was underneath the car checking the Sender wire and it seems fine.
What is strange is that it leads to the rear above the gas tank.
It would seem to me that it should be directed to the front where the
cluster is located...unless the wire harness is back there.
I drove the car and I'm still getting some intermittent speedo action.
Is there a chance that it could be some other connector?

Before you dig into the back any more, I check a couple of things up front.

Started to post this when you first posted but there seemed to be a Quorum on the rear connector.

I had the same issue with the speedo on my 86 after replacing the infamous gear. Actually had it twice, one was easy, the other took a bit to find.

Easy one first, reseed the connector onto the back of the speedometer by reaching up and giving it a good push with your finger. You can get there laying on your back with the cover off the drivers side and shine a light up in there. It is a three pin connector that come out the center back of the instrument cluster. A loose connection there you will get the jerky speedo.

That is the simple one, the other is a bit more involved but not that hard to do. The pins on the speedo have the same sort of design as the infamous temperature compensator board. You can't jumper these and get rid of the problem but there is a fix. Remove the cluster and take off the back of the panel like you do for the gear replacement. Just don't take the speedometer apart this time. Take an eraser and shine up the three pins on the back and get them clean. Check the plug on connector and make sure that is clear and something like a slug of butyl has not found it's way in there. Remove the speedometer from the pins to the board and take a small bladed screwdriver. The goal is to push in on the middle of the top side of the pins and snug up the contact. They can get loose over time and start making less than good contact. Clean the three pins until they are nice and bright also.

Installation is the reverse of removal.

Good Luck and may the herky jerky be gone.

Regards,

Paul

I'll definitely try these tips.
I can get the cluster out in 5 minutes or less after having to re-do
the odometer gear three times on my son's car.
Thanks Paul.
--
-Cool Volvo- 1982 240 4 Spd OD w/ 266K, 1989 240 5 Spd w/ 269K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

You don't have a speedometer cable as jomarex suggested. That applies to older cars with a manual speedo, yours is electronic and receives a signal from the sender in the rear differential. I had the exact same problem in an '89. I pulled the plug off the speed sending unit and tested the wiring for continuity to the speedo gauge. The wiring appeared to be fine so I replaced the speedo sender which I got a decent deal on from Amazon.com. Everything has worked great since!

Same here. I pulled the instrument panel a couple times, replaced the speedo head, fretted over all the wires. Finally gave up and turned to my mechanic, who replaced the speedo sender in the differential, and that solved it. He was surprised, said in all his years he'd never seen a bad sender, which is what I'd heard before and what led me to overlook it.

I figured that Jomarex was referring to the wire to the speedo.
I'll have to check the wire first before tackling the sender replacement.
Thanks for the advice.
--
-Cool Volvo- 1982 240 4 Spd OD w/ 248K, 1989 240 5 Spd w/ 241K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Brickboard duplicated my entry, so I figured I might as well get some use out of it. Here is a link to the thread where I solved my similar problem.

I believe that's exactly what mine was doing a long time ago when the end of the cable was really worn and about to break... Then if your transmission mount is shot, you'll have a bugger of a time getting the cable on.

good luck