Hello, 'bout at my wits end here. If it's not one thing it's the next. Just recently developed this problem. All of a sudden my speedo wants to not work right. Key on its fine, sits at zero. Start the car up, and it bounces around +/- 10-15 mph, even at idle it will jump up then back to zero, randomly. Seems to depend on how I have the cluster oriented, pressure applied etc. Thought I had it just right, then screwed in the remaining screws and it acted up again. I've checked all the connections at the terminals and they seem to make good contact, everything else on the cluster works perfect. Oh ya, also seems to do it over a bump or if I hit the dash downward. I tied the signal terminal screw on the back of the cluster directly to the wire at the terminal that plugs into the dash and it still does it. I would look elsewhere for a problem but it definitely seems dash related, or cluster related. I've swapped clusters with another and I get the same problem. Anyone else had a problem like this?

Thanks,
Ben

 

BTW, its electronic speedo.

 

hey, i had the same problem w/ my 90 r/s, it would read to 50 then die, then bounce. forst i went under the car and pulled the speedo gear cone and checked the teeth (urs may be electronic) the teeth were ok. i too was banging head, then my xsmn man informed me that the on board computer controls and monitors the gauges. so i bought a new OBC for about $120 from advanced and swapped out, problam fixed. now i dont know for sure if this is ur problem but look at it his way as i did. i had $120 or so, i would be getting a new OBC that I knew was new and since i was restoring the car aahh it was a plus even if it did not solve the problem. u can e mail me if u like @ brucelisar@gmail.com hope this helps...bruce

 

Thanks, I have another ECM I might try and swap

 

I have a similar problem with my tachometer. It reads extremely high. (2500 RPM @ Idle) and just recently it began to act erratic. It now jumps all over the place while all the other gauges stay accurate.

 

I've narrowed this problem down to a weak connection, where the plug mates with the cluster (really the PCB). Need to see if I can fix this, I have it temporarily 'rigged' with washers so it is just right, but its rock steady. If it moves in ANY direction it will flake out instantly.

Anyone know how to fix the copper trace on these PCBs?