So the temp gauge on my '85 Brat just stopped working tonight. Probably a bad temp sensor on the intake right? Cleaned the lead connector as well as the sensor prong.....still nothing. The electric fan does kicks on and off properly.

 

What's the correct test for a single prong sensor? Set a meter to read ohms, one lead to sensor prong the other to ground.....watch for resistance drop as coolant heats up.....if no resistance drop bad sending unit? Where is the ground for that harness that the sensor wire goes in to? What's the test for the dash gauge to see if its faulty?

 

I'm leaning toward either the sensor or the wire/ground because I can see the dash gauge bouncing ever so slightly.

Yeah, that`s the test.Or you could watch the voltage instead.(this confirms power from the meter)

 

FSM says:

DL 52@175F,23@220F

GL 154@120F,18@240F

 

Should be other flaky stuff if the ground is bad.

So the temp gauge on my '85 Brat just stopped working tonight. Probably a bad temp sensor on the intake right? Cleaned the lead connector as well as the sensor prong.....still nothing. The electric fan does kicks on and off properly.

 

What's the correct test for a single prong sensor? Set a meter to read ohms, one lead to sensor prong the other to ground.....watch for resistance drop as coolant heats up.....if no resistance drop bad sending unit? Where is the ground for that harness that the sensor wire goes in to? What's the test for the dash gauge to see if its faulty?

 

I'm leaning toward either the sensor or the wire/ground because I can see the dash gauge bouncing ever so slightly.

 

hi,

the sensor that turns on the fan is not the same one that works the temp guage, temp guage sender is on the back side of the intake manifold.

Yep, my issue is with the sending unit for the dash gauge.