Coolant Sensors and Switches: "Thermal Resistor"

[RandomThinker]

I'm scratching my head and hoping someone can enlighten me. According to the lmtv schematics I only see three sensors for the coolant system. They are shown in zones A-C57 on sheet 7. They are listed P36, P37, and P41. However on my truck I have four sensors, one of which is labeled P12 (or P42) on the physical wiring harness.

Looking up "P12" only shows the right headlight connector which is obviously not correct. Looking up P42 is the ether sensor switch which also doesnt seem correct since it's on a coolant line. This sensor is titled "thermal resistor" and is shown in figure 68 as item #7.

Does anyone know what it does and where it is on the schematic?

 

[Guruman]

Well, the ether system has temperature switch, because mine is not working. On my A0, it's right in front of the engine on the coolant pipe. It monitors the coolant temp to prevent the ether system from activation in warm temperatures.

 

[RandomThinker]

Ahh ok that makes sense. Thanks

 

[Ronmar]

4 temp sensors on an A0.
1. As mentioned for the ether system on the 1” crossover pipe that runs across and down to the trans cooler/heatexchanger. the information on this switch is conflicting, mine opens at 35F, so no ether above that temp.

2 For fan control, located on the upper radiator pipe between rad and thermostat housing. It provides power to power fan solenoid and keep the fan disengaged, and opens at 205F to release air at the solenoid and engage the fan.

3. One on the forward/inboard thermostat housing. That is a 230F switch that energizes the dash high temp light above 230.

4. One on the rear of the thermostat housing that drives the engine coolant temp gauge…

 

[Guruman]

1. As mentioned for the ether system on the 1” crossover pipe that runs across and down to the trans cooler/heatexchanger. the information on this switch is conflicting, mine opens at 35F, so no ether above that temp.

Anyone have a part number/source for the ether temp sensor?

 

[RandomThinker]

Anyone have a part number/source for the ether temp sensor?

MME seems to have them and so do a few others. Try searching "thermal resistor"
Alternates: QS11902SS, QS-1190-2SS, QS11913SS, QS-1191-3SS, 12421340, 5905-01-440-7331

 

[Guruman]

MME seems to have them and so do a few others. Try searching "thermal resistor"
Alternates: QS11902SS, QS-1190-2SS, QS11913SS, QS-1191-3SS, 12421340, 5905-01-440-7331

Thank you. Got one ordered. Saw several out there, none seems to be the right one in the diagrams.