I've got a head scratcher here. Only the right ambient light in my instrument cluster works. I swapped sides with the bulbs and sockets, but still only the right side works. It's not a bulb issue, its not a rheostat issue, and I am assuming both lights are on the same fuse. The rest of the instrument cluster works just fine (except for the useless shift light, of course!).

Anybody encountered this before? My best guess is the socket isn't making contact, and the issue would be with the cluster since both sockets work on the right side. I am hoping I don't have to go through the trouble of getting an entirely new cluster just to get one light working! (I will if I have to. I am pretty OCD about these things!)

 

I'd agree with your assessment... Contact points on the cluster board.

 

I'd pull the instrument panel off and inspect the wiring traces on the circuit board that connect these lights. you might need to clean the contacts of those sockets, I would use DeoxIT D100 sparingly, and gentle rubbing by a soft pink pencil eraser til the gold is shiny. the 2-3 illumination lights should all be in parallel, so use an ohm meter to confirm they have continuity between them. worse case, maybe solder some thin wires, like 'wire wrap wire' which is 28 or 30 gauge silver plated wire with very thin tough insulation, to reconnect things.

 

I am currently opening up the cluster right now. While I do that, I noticed something else. Last night I ended up removing the entire cluster to troubleshoot. I just noticed that my odometer hasn't gone up from last night. Everything else works, and I made sure to connect everything the same way I found it. What could I have messed up? I noticed there is a black switch on the back of the speedo. Would that have anything to do with it?

 

Take the speedo unit out of the cluster and check the gears. there are 2 gears inside it and the teeth on them fail with age. replacements are available at the dealer for $30 for both or you check the other online Volvo parts stores too.

 

I think I figured the odometer out. That black lever moves a gear to and from the threaded axle that changes the numbers. I had brought it out of contact. Welp, guess I got 34 free miles today!

 

the switch on the back of a newer 240 cluster is the Service light reset (said light comes on every 5000 miles).

 

Is it this (circled in green)? When I had the circuit board and out, I noticed that this lever was definitely moving a gear and motor assembly to and from a worm screw that changes the numbers. It sees to be loose and doesn't want to stay fully up or down anymore, just somewhere in the middle. It needs to be down to engage the gear.

 

yeah, I think thats it. not totally sure, our 240 is a 1987, and doesn't have a service light, my 740 does, but it has the reset on the front of the dash. its a mechanical counter mechanism along side the odometer gearchain, and the reset is much like the tripmeter reset, it takes a substantial push.

 

Well, I am at a loss. With the light that I can't seem to figure out and the odometer now, I almost want to take the lazy route and find a new cluster!

 

The circled item is the service light reset switch. If you pull another cluster, make sure you pull one of similar vintage. WOuld be best to go by part number stamped on the cluster. There are changes over the years.

I would opt to repairing yours. The odometer issue is typically due to broken teeth on the odometer gears as 240Fan stated. It is a common problem and odds are good that a unit you pull from a junkyard will have the same issue. There are good writeups out there that explain how to repair the gear.

As for you lighting issue, following Pierce's instruction should fix it. The circuit boards on these clusters are very easy to trace and should be relatively easy to repair if you are handy at soldering.

 

Thanks for all the input! How do I go about exposing the circuit board? It looks as if I would have to take the gauges out first.

 

Check out this site:

Volvo 240 Odometer Repair

It does a pretty good job explaining the odometer gear replacement procedure. Here is another:

http://www.odometergears.com/howto/V...eplacement.pdf