GM gauges

[corelokt]

I'm trying to figure out the o.e.m. type gauges. Three connection on each, power, out to the sending unit, and negative for return to zero. Where does the return to zero connection connect to? Is it a temporary ground source? and if so, where and how? Does a relay provide a ground switched off of a starting circuit?

 

[Crash_AF]

My 1983 Civvie wiring diagram shows a common ground and common ignition powering the gauges with a separate sensor wire.

Later,
Joe

 

[kennyw]

Most of the gauges would be grounded at the sending unit. I'm not sure if the dummy lights work the same or not.

 

[Crash_AF]

Double-checked my wiring diagram because I misunderstood your question... the ground goes straight to the main ground under the dash, it is not switched.

Later,
Joe

 

[corelokt]

Thanks guys, that saves a lot of trouble.