Hey,

1991 z28, 58k miles.

Normally, my speedometer works fine and is accurate. But every once in a while the speedometer starts acting erratic. Either it will not register at all (needle stays down at 0), or it will bounce up from 0 toward the right speed and then back down.

When this happens and it registers no speed… the odometer doesn’t increase either. Everything else is fine. Car is stock other than normal wear parts.

any thoughts on what’s going on? I haven’t noticed a pattern to when it won’t work either… very weird.

thanks!

 

I sent mine in to be rebuilt and it works perfect again. Had the same issues you had on both my Tach and my Speedo board. The speedo board you cant find anywhere for sale so it has to be fixed: 1990-92 Chevy Camaro Speedometer Circuit Board Repair Service (wc-autoparts.com)

This includes replacing parts that don't test right, cleaning the contacts, and resoldering where needed.

 

Thanks StevenK. Did they end up telling you what was wrong? I have a Tach issue too, but that's the very common one where it reports much higher RPMs that reality... but I've seen that's easy to replace via the $45 replacement board you can buy. Was hoping someone knew of a similar fix or resistor replacement that might be causing this issue. Looking at the link you sent, it seems you can't buy the board because of old parts no longer available or firmware on the chips that you can't get/re-load. So, the repair service makes sense. Thanks!