Hey guys I have an 87 GMC 1500 with a 350. My problem is as not 2 min after starting my truck the temp gage sky rockets. it wasn't working at all until I recently replaced the thermostat and the temp. Sensor on the side of the block. I just put a manual gage in it but would like to get the stock gage in the dash working. Any ideas???

 

My son had a similar problem and it turned out to be the cable that attaches to the sensor. Good luck.

 

When the gauge bounces around, does the truck run or idle different or crappy?

 

It runs fine the whole time I will try that thanks

 

Is your other gauge running off the same temp. sensor?