Hi,

I have a 1986 Volvo 240 DL and I swapped out the instrument cluster with one I found on eBay because the mileage reader was no longer working. (I had tried changing the little internal gears on my original cluster before replacing it with no luck).
Everything seemed to match up perfectly except the instrument cluster lights that go on at night when the headlights are on don't work.

The issue appears to be because the lighting components are different on each of the clusters.

My original one from 1986 has larger styled bulbs with a larger black casing. The one from 1993 has a slightly smaller bulb that's in a red casing and appears to need a cable plugged into the back of it to power the lights. My one from 1986 had no cables plugged into the back of these bulbs.

1 - Am I correct in thinking the 1993 bulbs are powered by a cable that gets plugged into it?
2 - If I am correct does anyone have any suggestions on how I can get power to these bulbs so they work in my 1986 Volvo?

Attached you will find pics of the 1986 and 1993 instrument clusters. The closeups are of the specific bulbs/casings I'm referring to in each cluster.

Thanks!



1986 - back of light bulb casing



1993 - back of light bulb casing



1986 instrument cluster

1993 instrument cluster

 

The size of the bulbs should make no difference, and I don't think there is a separate power source for the '93 cluster. Have you looked into the dimmer rheostat switch?

 

The size of the bulb/container matters because the black ones (they’re too big) don’t fit into the cluster that has the red ones in it.

The rheostat works fine, when the original cluster is in the lights light up and dim properly as well.

 

The brown wire at plug 31, terminal 10 is the same for both years. "12v from rheostat" , Do you have "12v from rheostat" at that wire? If so the problem is in the cluster. Either bad bulbs or circuit board problem -

 

Well that's good because you're saying no cables directly into the back of the bulb containers then, and yes as previously stated the rheostat works perfectly fine with the other cluster so 31/10 is in place.

I suspect the bulbs might be bad BUT how does one test them?

Also where do I find replacements for those bulbs/containers? They are all one piece, with the bulbs being non-removable from them. Tx.

 

Test with your $10 volt -ohmeter



Buy new ones here
https://www.fcpeuro.com/products/vol...xoC8tMQAvD_BwE

 

Never knew my multimeter could test bulbs as well, lol.

Thanks for the link, purchasing now.

 

It was indeed the bulbs, all is good now.