Carbureted LSX Forum - ls motor in 86 Iroc coolant sensor/water temp

03-09-2012, 11:57 PM
Wanted to know if its possible to run the factory water temp sensor from the ls style motor and wire it into the factory iroc cluster. Is the resistance values the same for the iroc sensor and the ls sensor. I was looking at the schematics and it shows that the sensor for the iroc grounds itself out onto the block then the signal wire runs through the gauge cluster and shares a common ground with the oil pressure and tachometer.

The ls style sensor shows that it gets a "low reference" that goes into the "A" side of the sensor then goes through "B" which appears to be the signal wire that goes into the pcm. I am having a bit of a problem trying to figure this one out. Is it possible to add two power wires into the sensor and let it ground its self off on the block then let the voltage drop from the resistance pop it up on the gauge...kinda hard to figure this one out when I see two variable resistance values on the ls style sensor?

Thanks in advance RoLo

03-10-2012, 05:50 AM
meh...Id just run a mech gauge:jest:

03-10-2012, 08:29 AM
There are adapters available to let you use the stock sensor.

Pop N Wood
03-10-2012, 09:30 AM
Is the resistance values the same for the iroc sensor and the ls sensor.

That is the important question you need to answer.

Looks like both sensors are just variable resistors. so yes, you could just hook the one wire from the IROC cluster to one pin and ground the other. Shouldn't matter which one.

Before you do that hook up the sensor to the car with a set of jumper wires and put it in a cup of hot water with a kitchen thermometer. Run the water temp up and down to see if the gauge reads right. If it doesn't, then look into the adapters

03-10-2012, 07:41 PM
Thanks for the replies. I will try the resistance check, as far as the adapters and mech gauge that was an idea being thrown around but it would be nice to have all the factory gauges functional so I will try that first.

03-17-2012, 09:31 PM
street and performance sells 12mm x 1.5 adapters to 1/8,1/4,3/8 and 1/2 npt...just ordered mine thursday.

03-25-2012, 07:55 AM
I don't know if you've seen the thread, but I got the '98 3-wire CTS that threads right in: