John Deere Gator Forums banner

ProGator 2020a

181 Views 3 Replies 3 Participants Last post by  200mph
I have a ProGator 2020a with Yanmar 3 cylinder gas engine. The cooling fan runs when the key is turned on whether the engine is running or not. The fan will then randomly cycle off and on - it does not matter if the engine is on or not. The gauge is also random but follows engine temperature somewhat.

There are 2 sensors on the thermostat housing. One with 2 wires the other with multiple wires. I cannot properly identify either sensor in the JD parts diagram and which sensor operates the fan and which operates the gauge.

I am looking for the proper sensor identification and part numbers.

I have trouble keeping my wife off of it. Once she learned how to drive, it is HER yard tractor.... and it saves me a lot of work....
1 - 4 of 4 Posts
Have you checked to see if there is a sensor on the radiator core?
For around $30 you can download the TM1759 tech manual that has the wiring diagram in it. A handy thing to have regardless.
I checked it again yesterday.... both sensors are located in the thermostat housing. One sensor has 1 wire. the second sensor has 4 wires. Obviously you cannot tell what is inside of the sensor but there are 2 sets of 2 wires going into the sensor. As soon as I have a few minutes, i am going to start disconnecting the leads - the single is simple. the other will have to go back to a moulix connector some
  • Like
Reactions: 1
Many times one sensor is a thermal switch with only two wires powering the fan. Its function is off/on based on temperature.
Simple enough to check continuity of sensor using pot of hot water and noting at what temperature it changes state.

Other possibilities exist but this is something you can check.

Technical manual with wiring diagram will spell out the details as there have been difference between models and years.
1 - 4 of 4 Posts