92' GMC thermostat problems
 

My thermostat needle does not budge (literary, turn it on and off does not move). Any suggestions on what it could be?

Its a Sierra.

The sensor for the gauge is on the drivers side of the block and has a single wire going to it. Make sure it is plugged in and if so, try grounding the wire to see if it makes the gauge move. If it still doesn't move than the guage itself is bad or you have a broken spot in the wire somewhere.

mhmmm. Me and my Dad took a look under the hood and there is one wire not plugged into anything. When I change the air filter tomorrow I'll post some pics.

Correction, heat gauge not thermostat

Here is a image of the wire.

Hmm I have no clue what that wire is. Doesn't look like anything that's on my truck. Maybe the A/C compressor clutch wires?

mhmmm. Thinking the engine might not be stock....so any one know what the heat gauge issue could be?

Did you check the sensor on the drivers side of the engine?

Nope, is there a way to check it digitally or would it have to be done manually?