E30 speedometer and odometer

[whaaac]

for the e30 gurus
since the common problem for e30s is that the speedometer and odometer.
how do you know for sure it doesn't work?
for my 84 325e, the speedometer and odometer work once in a long while but its usually just dead.
do you think its the wires that's not connected correctly or is this the problem of the e30s?
help!
thanks guys!

[MrBurgundy]

When your driving and the miles don't change. That's how you know. :drink:

[slammin.e28]

Speedometer would be the SI board, correct guys? Unless the sender at the rear diff is going?

Odometer would be the gears, but usually they just stop and are done.

[whaaac]

Speedometer would be the SI board, correct guys? Unless the sender at the rear diff is going?

Odometer would be the gears, but usually they just stop and are done.

people have been telling me that its the plug that is connected to the differential.
thing is that sometimes (rarely) whenever I drive over a bump or something the odometer and speedometer works for like less than a mile or two.

[Nick_S]

Sounds like a bad connection. Part it out.

[whaaac]

Sounds like a bad connection. Part it out.

where do you think i should start?

[Nick_S]

where do you think i should start?

Sorry that was meant to be a joke, like part the whole car out. I suck at the internet.

But on a serious note. I had a neon that did the same thing. Hit a bump and the whole cluster would go down. Had a bad connection at the harness on the back. Pulled it out, cleaned it real well and made sure it was secure and it went away.

[Gasturbine]

Usually cold solder joints in the cluster. Pretty easy fix if you know how to solder.

[jeffnhiscars]

I have new gears in all 4 of my e30's but one of them still has an intermitent speedo. A smack to the cluster gets it going so its surely a bad connection or solder joint.