I've installed aftermarket electric gauges in my Firebird which I've installed a 96 LT1 into. The only gauges working are the speedo and voltmeter. No tach, water temp, oil pressure or fuel level.

I've already double checked all the wiring and grounds and everything's like it should be.

How can I check the wiring to see if the gauges are getting signals from the sensors? I'm trying to troubleshoot and I don't know how to read the wiring with a voltmeter. Don't know the setting. Any help would be appreciated.

 

there should be roughly 5v at the positive sides of each gauge.

 

So can I just put a voltmeter to the signal wire coming from the sensor while the engine is running?