3 Wire Camaro Coolant Temp Sensor Resistor.

[Big-Sexy907]

Does anyone know off hand what resistor value is used when using a camaro 3 wire coolant sensor to read off the factory dash gauge? The truck is a 1990 C1500... this is one of the last gauges I need to read correctly.

[Chris]

I haven't seen a definitive answer for that question, most people either live with it being off, or they use the stock sensor installed in the engine in another location (which is what I did). I had the stock sensor (a few of them) turned down on the lathe and threaded to fit on the passenger rear head and just used my stock wiring to the gauge.

[Big-Sexy907]

I considered moving the stock sensor to another location, but thought it would be nice and convenient to use the camaro 3 wire... Lookin at my gauge it says I'm around 30-40 degrees hot.

[Chris]

Easiest way I can think of to figure it out, which I'm not even 100% sure if it will work or not, but get a potentiometer from Radio Shack, install it in place of the resistor, and adjust it until the reading on the instrument cluster is the same as the reading in the ECM, then measure the potentiometer for your correct resistance value.

[GreyChevy]

I haven't seen a definitive answer for that question, most people either live with it being off, or they use the stock sensor installed in the engine in another location (which is what I did). I had the stock sensor (a few of them) turned down on the lathe and threaded to fit on the passenger rear head and just used my stock wiring to the gauge.

I just noticed that my 92 k1500 with 6.0 swap reads about 20 degrees cooler than the actual coolant temp is. Is that due to the adapter taking the stock sensor out of the direct line of the coolant?

[Blasphemy]

That's not a bad idea using the potentiometer, I'm definitely gonna have to try that. I have the 3 wire camaro gauge and I'm pretty sure I'm reading about 10-15 degrees off but I'll have to check reading in the ecm vs the gauge

[Big-Sexy907]

Easiest way I can think of to figure it out, which I'm not even 100% sure if it will work or not, but get a potentiometer from Radio Shack, install it in place of the resistor, and adjust it until the reading on the instrument cluster is the same as the reading in the ECM, then measure the potentiometer for your correct resistance value.

That's actually a darn good idea... As of now my coolant gauge still shows a reading even with the key off. Talk about irritating.

[Skylark]

How about looking at the data on a scanner and popping the needle off the gauge and putting it on in the right spot? It should be linear so the lower end of the gauge really doesn't matter.