Alright I did the trick grounding the white/red wire of the temp sender plug to a clean ground and tested the temp gauge. The gauge went to hot so I know the gauge works and that wire works. Weird thing is that someone spliced in a new plug to the temp sender. I replaced the tepm sender and temp sensor now and still no temperature reading on the temp gauge and the fan still only comes on when the ac or defrost settings are used. I guess I shouldn't be worried about overheating since I've replaced and checked everything. I just wish I could tell what the hell is causing all of this. Could the relay in the engine fuse box for the motor fan be bad and how do I know? Anyone know how much one of these costs?
