gauge cluster works after you hit it

[Dr. Anthony]

So my gauge cluster on my 91 318 is intermittent. When it stops working, it'll come back on by hitting the top of the dash (above teh cluster)

1 hit and you see the needle jump up to around 100k/h and then bounce back to the normal speed I'm doing (20k/h at the time)

everything else appears to work fine. Does this still sound like a gear issue? or could it be something else?

[dnguyen1963]

Check the cluster grounds. Clean the posts and tighten the nuts should take care of the problem.

[Dr. Anthony]

Check the cluster grounds. Clean the posts and tighten the nuts should take care of the problem.

thanks i will give that a try

[muppetman342]

check the cluster grounds. Clean the posts and tighten the nuts should take care of the problem.

+1

[Dr. Anthony]

Which grounding posts are you referring to?

The 2 goldish colored ones on the back of the cluster (attached to the temp, and fuel level gauge)?

[Dr. Anthony]

I removed the cluster and noticed the nut is missing from the back of the fuel level sensor. Could this be related?

pics attached

[muppetman342]

I removed the cluster and noticed the nut is missing from the back of the fuel level sensor. Could this be related?

pics attached

That definitely isn't helping. Those are the grounds for those gauges, I had the same thing and replacing that nut solved my problems.

[dnguyen1963]

It is a good idea to check the main board too. Look for any cracked solder.

[jgilber0]

I cracked a vinyl dash doing that once. Careful!

[Dr. Anthony]

I cracked a vinyl dash doing that once. Careful!

I wasn't hitting hard. Literally a light tap :)

I'll be looking at the cluster this evening once the kids are asleep:yawn:

[Dr. Anthony]

I just tested the batteries on my SI board.
each battery reads .81v

Replace em?

[jgilber0]

I wasn't hitting hard. Literally a light tap :)

I'll be looking at the cluster this evening once the kids are asleep:yawn:

That’s good :)

I’ve had my cluster in and out and apart four times. Still not working quite right. Good luck!

[dnguyen1963]

I just tested the batteries on my SI board.
each battery reads .81v

Replace em?

Yep.

[Dr. Anthony]

Just wanted to update the thread.
I think the problem is solved. I replaced teh little ground nut behind the temp gage and cleaned up the contacts. Went for a test drive, and everything seemed to be OK.

Time will tell.

I *didn't* replace the batteries, but I will order some and replace when they're in.