instrument cluster cpu board fix

[dovstar]

I've owned my car for 10 years and I've always had intermittent display/gauge failures due to the board behind the cluster acting all funky. I've replaced that board 3 times because that's what was recommended. One time before I flew out of town my cluster had stopped working. While I was away I the battery died and I had to get a AAA boost. Magically the cluster started again. It worked for about 12 months without a problem. One other time I had a new mechanic check the board and replace the capacitors. Yesterday the electronic displays and temp and fuel gauge stopped working so I disconnected the battery for 15 minutes this morning then connected it and everything came back on. We'll see how long this lasts, but it sure beats paying $650 for a rebuilt board.

[eightynine535]

when your mech changed the caps did he use a higher temp cap or just replace it with stock?

[dovstar]

good question. I don't know. Which is better?

[slocar]

Higher temp. The way a capacitor fails under normal use is it overheats and leaks out.

[dovstar]

This sounds like good advice but how does disconnecting the battery explain the fix? This could be a different problem then.

[Duce735sanda318]

Good Morning,

In regard to your posting about a dead instrument cluster in an e34, I have the same problem except mine is DOA completely. I have lights but no reading for any of the gauges (Speedo, tach, gas or temp). The car sat overnight and the next morning, still DOA.

Is there any reason why you disconnected the battery for 15 minutes the first time?

Do you have any idea where the board is located or if this is a DIY job?

- If I can find a DOA e34 with an m20 engine like mine, maybe I can source the part used, replace the capacitors and replace mine. It is always good to have spare parts if it is a simple fix.

I am hoping that is a fuse issue and because I found moisture at the base of the windshield on my drivers' side after it rained last night. Right now I have my fingers crossed that sealing the windshield and replacing the fuses will work...because pulling the dash and chasing electrical demons will not be fun or cheap!

[HausBimmer]

Is there a spec/code or number for the high temperature capacitors?

[zubbie]

There is a link for the fix here.

http://www.bmwe34.net/e34main/maintenance/electrical/capacitors.htm

Also note that instrument cluster problems may be associated with bad fusible link also

Same web site http://www.bmwe34.net/e34main/maintenance/electrical/fusible_link.htm

[bam2002]

I am having all the gauges stopping for about 10 sec then working OK again for the next 30 min.. I have a spare cluster, But I think i will try the Fuse 1st.. I would bet its never been looked at..
It was a neglected car..

B