E30 Instrument cluster not working.

[lcc9115]

I'm sure this has been brought up before but I am getting different answers from people so just want to clear it up. The car is a 1993 E30 325i vert.

A few months ago my Tachometer stopped working. Started to jump then cut out completely. Recently my Speedometer started to cut off when I let off the gas and come back when I hit the gas. Now is basically stopped working completely only coming back up when I am on the gas.

I read that the batteries on my SI board are dead but a mechanic told me I need to replace the entire instrument cluster. I can probably replace the SI board myself but not the cluster. Big cost difference.

Any thoughts/experience with this? It's tough to drive with the instruments starring me in the face not working.

[delatlanta1281]

Take your SI board to batteries plus and have them solder new batteries in it.

[Gregs///M]

I would start by replacing the fuses for your cluster. They are fuse 10, 12, and 21 all 7.5A. Don't check them, just replace them.

If that does not work, I would go ahead and proceed with replacing your SI board batteries. Also check the connector at the rear differential. That is the speed sensor connector and it is well known to get dirty, corroded, and loose. Clean it up, and tighten up the connection and your speedometer might start working again.

[saturnv7890]

It also takes 25 mins tops to pop out the cluster and tighten the ground nuts on the back, but I'd do that after the fuses and when you're ready to test those SI batts

[Jdesign]

Awesome!! I have a 93 325 vert with the same issues starting to brew.

[lcc9115]

Thanks, I'll try to fuses and go about replacing the batteries. The mechanic I've been using said the batteries have nothing to do with the tach/speedo but too many people tell me otherwise.

[dnguyen1963]

Your mechanic does not know how BMW works.

[Gregs///M]

+1 on your mechanic not truly familiar with BMW cars, especially electronics.

[2761377]

It also takes 25 mins tops to pop out the cluster and tighten the ground nuts on the back, but I'd do that after the fuses and when you're ready to test those SI batts

trying to meet that 25 minute deadline is a good way for a noob to break both tabs off the cluster.

noob, give your self 3 hours and just get the si batteries replaced while the cluster is out.

hth
robert w.