Pontiac Repair: temperature gauge not working, proper test equipment, temp gauge

Question
i have a 1986 pontiac trans am 305 tpi 4 speed auto and my temp gauge doesn't work. any help would be appreciated

Answer
Hi there:

Well it could be either the gauge bad or the sending unit on the engine. more times than not the sending unit goes bad before a guage goes bad.The sending unit is in the cylinder head and it has a dark green wire on it. With out the proper test equipment I can't tell you for sure which is the bad part. there is a test tool that you hook up to the green wire and you can make the guage sweep up and down that test the wire from the sending unit to the gauge.