1988 S10 blazer V6 4.3L

Im having trouble diagnosing and fixing a problem with my temp gauge reading zero.

I have changed the sender, which resulted in an immediate reading of MAX.

When the car's ignition is in AUX there is voltage going to the unit, but no temp reading, BUT when the car is turned on, no voltage is read going to the sending unit.

Any ideas?

 

When you installed the new sender unit you didn't wrap it in teflon tape did you?.. it needs a good ground.
Do all of the other gauges in the cluster work? I would check to make sure that you have a good ground to the gauge cluster.

 

quick question. i changed the coolant temp sensor on my 86 s10 blazer with the 2.8L V6 and when i changed it i put teflon tape on it would that affect anything?

 

no, teflon tape was not used. i wanted to make sure i had a good ground.

if you have put teflon tape on the sensor unit, and it is working, it should be fine. i just wanted to rule out the possibility of having a bad ground