[Stephen Morrison]

Does anybody know how the GM temp sensor/gauge works. My thinking is that power goes in the guage. That power comes out the other end and it grounds out through the sensor. The hotter the senser gets the more current it lets through. I have two gauges that if I hook up to the batter on the + side and run a wire from the - side to the sensor I do not get that result. I can't find any test methods or normal ohms reading for this two items. If i ground out the sensor the gauges peg.

 

[charlo]

I thought for some reson the power went from the guage to the sensor. The sensor grounds to the block on my 350. My TBI454 looks like the temp has 2 wires coming off of it.

Charlo

 

[Stephen Morrison]

yours sounds newer than mine. I have an 82 and the sensor has only one spade.

 

[rcurrier44]

Every temp guage I recall seeing run a +,-, & signal. This is the way the stock guage works, the signal line runs power to your sensor, witch has a resistor in it that changes its resistance depending on the temp in its enviorment (your coolant).

Watch it with using the stock sensor mounted in your head. You will find the temp running around 240-260 in that area of the engine. My guage only went up to 280 so I thought my engine was overheating untill I grabed a pyrometer and meashured the temp at several places in the engine. Then I pulled the stock guage out of the guage cluster and it read normal. So If your guage is pegged it might acualy be reading correctly.