For the last few months my temp guage has been very erratic. Sometimes it works just fine, other times it stays at cold or bounces between operating temp and cold. Yesterday I pulled the sender out of the back of the engine, cleaned it up, and tried to adjust the wires so they werent at such an angle--no go, same as before. I went to my local Worldwide Auto parts, but the sender they have listed is all wrong (way smaller)-

Am I looking at the wrong sensor?

I need this fixed-I just installed a taurus fan and it makes me nervous.

Note: this is on a 95 runner with 3.0

 

Funny -- I just had the same problem. Ended up being a small leak in the rear coolant hose. It wasn't big enough to drip (yet), but every time I stepped on the gas to accelerate hard it created enough pressure to squirt fluid on the sensor -- causing the temp gauge to fluctuate between normal temp and cool temps.

I found it by pressure testing the coolant system, and then replaced the hose.

Ed