Temperature gauge

[Tanner1976]

Hello I have a 1976 Chevy K 20 I’m having an issue with a temperature gauge. If I ground the wire the gauge goes to hot as it should so I figured it was the sending unit I replaced the sending unit and it’s still only stays on cold

 

[AuroraGirl]

Perhaps the gauge works by varying voltage through a sender(usually on the driver side head) and its either not meeting resistance, the cooling system has a pocket of air there keeping it from circulating heat to the sensor, or the new sensor is bad, or the wire is broken and i would assume a broken, but not grounded, wire would return no signal.

I dont know how the 1 wire gauge sensor works, but im spitballing.

Ive put my valve cover on sandwiching the sensor. maybe it broke the wire.

 

[80BrownK10]

Perhaps the gauge works by varying voltage through a sender(usually on the driver side head) and its either not meeting resistance, the cooling system has a pocket of air there keeping it from circulating heat to the sensor, or the new sensor is bad, or the wire is broken and i would assume a broken, but not grounded, wire would return no signal.

I dont know how the 1 wire gauge sensor works, but im spitballing.

Ive put my valve cover on sandwiching the sensor. maybe it broke the wire.

I wouldn't think a broken wire because if he grounded the wire to the block nothing would happen.

 

[AuroraGirl]

I wouldn't think a broken wire because if he grounded the wire to the block nothing would happen.

Does the sensor work by varying ground? Using the resistance?

 

[80BrownK10]

Does the sensor work by varying ground? Using the resistance?

I have no idea I just know most old school gauges peg out when you ground the wire. So I'm guessing that would be a yes? Resistance plays a part somewhere in that sensor is assume.

 

[Big red square]

I'm having the same issue.
Did you ever figure this out?

 

[Snoots]

STOCK GM Temp gauges have one side to switched +12.
The other wire goes to the sensor. The sensor varies its resistance depending on the temp.
Do not use Teflon tape on the sensor.