I have a 2000 Saturn LS1 Driving down the road all instrument gauges stop working. I pulled over and switched car off and restart car they went back to working could this be a grounding problem?
The gauges are controlled by a serial data circuit which feeds information to the instrument cluster. Not so simple, like in the past.
The correct procedure is to install a scan tool and check for trouble codes in the Powertrain Control Module and the Body Control Module memory. Often times a trouble code will lead you in the right direction of the fault, which may require further diagnostics with a digital volt/ohm meter.
Possible causes can be a lot of things, and I don't see any related technical service bulletins. It could be a poor ground or power feed to the cluster, a bad connection in the serial data line, and so on.
If I had to guess, it might be the cluster itself (internal problem requiring replacement) or a poor terminal connection at the cluster connector. You might try banging on the dash a few times with the ignition on. If the gauges shutdown or jump around on impact, it's probably the cluster or cluster connection.
The cluster terminal should be checked by inserting a correct male terminal into the female terminal to be sure there's a notable drag going in and out -- loose is no-good.
If it only did it once, I'd wait until it happens again before investing any time and money.