Hi,

I was wondering if anyone else here might have some idea's. This is for my son's car, 1995 Mustang, 3.8L. His temperature gauge would go beyond hot and every once in awhile it would retreat back to a proper reading. He just replaced the coolant temperature sending unit and it is doing the same thing. He also says that the fan is coming on all of the time after replacing the sending unit. He also says that the plastic one wire connector looks worn. I had him just splice in a wire from the feeder wire to the coolant switch with no different results. I don't have access to the schematics, can you give me some idea of what this circuit looks like? Is there a relay? Does the gauge signal split off and share the wire to the ECM?

Thanks, I would appreciate it.
Thomas

 

I had a problem like this (not 100% the same) and it turned out a wire in the pass side wheel well has shorted out and it was causing my temp to rise out of the normal temp range. I think it was causing my fan to not kick on. But you might have a headgasket starting to fail ( a VERY common problem with our 94-95 stangs)...

Matthew