3840 Coolant Temp Sensor

hlpdobro · Apr 13, 2019

Not getting a reading on the temp gauge and havn't located the coolant temp sensor (or whatever Montana/Mitsu calls it). Would someone kindly point me towards the sensor location?

Thanks in advance.

hp

Lgim · Apr 13, 2019

purely from memory I'm going to say top front of the engine close to the thermostat. A couple years ago I was having heating problems on my 3040 and when I pulled the thermostat to test it I remember seeing the sensor close and thinking that also could be my problem. I'm not near the tractor so I can't go look, sorry. My guess would be corrosion where the wire connects to the sensor.

gary

ramonajim · Apr 13, 2019

It's right under the thermostat - front of the engine, where the top radiator hose connects.

I've got the same issue on my 3840 - checking the sensor directly, the resistance changes as the water heats, hits a stable level (around 550 ohms) once the engine is warm, then goes up and down as the thermostat opens and closes.

Temperature gauge never moves. Tomorrow, I'll be popping the dash open and trying get to the root cause.