1973 1800ES:

I hope this makes sense....

After reinstalling the dash I'm attaching the wiring and re-installing/connecting the gauges.The dash was disassembled for WAY too long and, even though I know where all of the wires terminate, I can't recall exactly how the wiring routes to get there. The main part in question is the largest of the wire bundles that comes up from the fuse panel and then runs behind the dash, left-to-right, feeding gauges and switches along the way. I currently have that large harness held up to the bottom side of the dash above the fuse panel, with a harness clamp, per original configuration. Moving to the right from there, i have the bundle wedged between the backs of the tach/temp gauges/speedo and the steering column support. That runs it against the smooth side of the column support but makes things very crowded and difficult to connect the temp gauges in particular.

Should that large harness run across the FORWARD side of the column support?

Anyone have any photos that might help?

Thanks.

Unfortunately the harness is routed directly behind the gauges.

I usually remove the tachometer to access the voltage stabilizer and/or the 2 temperature gauges.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

"...Unfortunately the harness is routed directly behind the gauges.

I usually remove the tachometer to access the voltage stabilizer and/or the 2 temperature gauges..."


Ugh! That's what I was afraid of. I got the stabilizer in and connected. Then I installed and connected the upper temp gauge. But then I installed the tach next, before the lower temp gauge. I'll try removing the tach in order to get the lower temp gauge in and fastened. It appears to me that the lower temp gauge will be pressing firmly up against the wire bundle. We'll see how it goes.

I'm tempted to disconnect the illumination (red wire) daisy chain from the rheostat and get it out of the way until all the gauges are in. It's kinda adding to the rats nest.

Thanks!

I would be happy to send you a photo of what I just did but after reading what Eric said I'm not to sure I got it right, he would know far better than I. Tried to copy another P1800 but very hard getting around an aftermarket AC unit that is mounted under dash plus used photos of mine before removing dash out of car some 10 years ago so records are not to clear to me now.

Sounds like you're on my schedule.

I got it all wired up. I had the advantage of no steering column tube, no steering wheel, no defrost ducts, A/C unit out of the car, seats out, etc. (I had the dash out of the car for a re-cover job.) I removed the bracket that anchors the steering column and that was the ticket - it gave me much better access to the back side of the speedo, tach, temp gauges. After I had it all wired up I put the bracket back in.

Before I put all the stuff back in the way I want to connect the battery and do the smoke test. I'm just nervous about doing it.

Good luck with your project!

Chris;

"I want to connect the battery and do the smoke test. I'm just nervous about doing it." ...don't be nervous!...for initial power-up tests after major work, I recommend limiting energy available from Battery! See: http://www.sw-em.com/Battery%20Notes.htm#limiting_available_energy

Good Hunting!

Ron,

Thanks for that info. I was wondering if I could rig something like that but I wasn't sure what amp fuse I could use. Too high and it doesn't offer adequate protection. Too low and it will blow from the load(s) even if there is no short. Maybe I'll use a fuse that is like 5 amp larger than the largest fuse in the fuse panel, and then test one accessory at a time.

Fortunately I mostly disturbed the wiring down stream from the fuse panel so I'll have that protection also.

Now I just need to dig through my parts heap and find an inline fuse holder. Let's see, I know I saw one somewhere.......
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

Chris;

Remember, when in series and passing current, be it normal operating or simply test current, the weakest link will heat and fuse first!...so any fuse value higher than that drawn by the various loads you'd be testing, and total current you'd be drawing, during your check-out (one at a time), would do it...but a 10 or 20A would be good to protect even the smallest gauge used in the car (18Ga?)...and if you can't find that fuseholder you remember having (SOMEWHERE!), simply use a smaller gauge (22Ga) or even a few strands of wire from a heavier gauge wire...this fuse "or frangible link" is really just a last ditch safety measure that you don't expect will blow anyway during testing.

As far as upstream or downstream...you can't get any more upstream than at the Battery...THE energy source, when engine (CHG SYS) is off-line.

Good Hunting!

Well, I powered it up - no sparks or smoke! Used a 20 amp fuse inline at the battery terminal until I got confident and connected the battery cable direct. Outside of a missing W/Wiper switch, things seem to be working pretty well.

One disappointment though is that the instrument lighting is very dim. Even if I take the rheostat out of the equation (full current to the bulbs) they're awfully dim. All the bulbs are equally dim which makes think I have a bottleneck in the wire somewhere. All the instruments are properly grounded. There is little or no drop in voltage when the lights are turned on, so I'd guess I'm OK on the supply side. The bulbs are 3W which agrees with the info on the schematic. Are these lights inherently weak?

Chris;

Congrats on smokeless initial power up!

Inst Lighting should get full voltage when control is set to Minimum Resistance/Maximum Voltage...I'd measure this first (at Lamps!) and verify...dim Lamps when they are getting full voltage can be due to filament plating onto inner glass and making it difficult for light to get through (example of this shown below)...only remedy for this is replacement of Lamp(s) exhibiting this...but verify Lamps are getting full voltage first!


Good Hunting!

I pulled a couple of the bulbs out of their instruments and grounded the bulb holders. They illuminated brightly. I even grounded one of them through the metal tube that it inserts into on the back of the instrument, in the event that I had poorly grounded instruments - still lit up bright. But it just doesn't seem like the instruments were very well lit or easily read last night in a near-dark garage. Could it be that's "just the way they are?" Or could it be old eyes? What about upping the bulbs from 3W to like 5W? I hate to risk melting the holders. LED's?

I'll try and better simulate a true night driving environment in the garage tonight and see if I actually could drive the car.

Thanks for your continued interest.......

Chris;

If electrical connections are all good and light output from incandescent Lamps is at max but still getting lost in the fixtures as Eric suggests, it's a fixture issue (reflectors or reflective surfaces? diffusers? etc)...and you cant simply increase the light by increasing the wattage because that will, as you suspect, increase waste heat which can damage things...so an LED solution might be interesting, but you would have to do some trial and error and engineering of the brightness control/current limiting. The trick is to use white LEDs at a current which will result in brighter light output, undoubtedly less heat than the incandescent but hopefully with more light to offset the losses in the fixture...they still MAY need some heat-sinking to shed their waste heat. Contact me directly if you want my help on this.

Cheers

Ron / Eric,

I just went out into the dark garage, got in the car and turned on the lights. Although they're weak, I think I'm going to say they're tolerable for now and go with it. I can see the needles just fine - it's the scales on the smaller gauges that sort of need to be memorized before hand. I have a enough other tasks ahead of me that I need to move past it.

Stand by for the next chapter entitled "How to Hush a Squeaky Fan Motor".

Thanks, all.

The dash lights have never been great for the 1800E/ES.

This is because the light from the bulbs has to be reflected around the perimeter of the faces and if the reflective paint on the inside of the housing is dirty or flaking, it will be dim.

So LEDs are the way to go.

IIRC, you want LEDs with a wide angle of light dispersion.

The only problem can be if you get LEDs that are too bright. You can't dim standard LEDs with the stock dimmer.


--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502

Excellent Chris, I think you are a bit ahead of me on rebuilt. The steering column was key, my car is on a rotisserie and I did all the wiring on bench after rebuilding the dash panel. It was a lot easier for me to do the re-install as I had the car upside down and stood though the windshield opening to complete wiring and everything else under dash/firewall. In retrospect now I should of installed windshield before dash and worked through door openings as I think it is going to be hard to get the lower windshield seal seated well with dash in the way, I might have to loosen up the attachment hardware and try to move the dash a bit aft.... I'll let you know in a few weeks how it goes.