Hi, just bought my first chevrolet.
Its a Chevy van G20 -90 with the 350 v8.

The water temp gauge does not work.
What is the most common reason they dont work? The gauge itself? The sensor?

Where is the sensor located?

Is the sensor easy to get to and replace or I might aswell buy an aftermarket gauge and install right away?

/ Jim, Sweden

 

The coolant temp sending unit is on the drivers side of the head between the spark plugs. That is the one for the gauge. The other one by the thermostat housing is for the computer.
Take the wire off the sending unit on the head, and ground it. When you turn the key on, your temp gauge should peg to full hot.
If that happens....its the sending unit. If not, then it could be the gauge or the wiring.