YM 155D Location of temperature sensor switch.

[astromarmot-HT]

Hello everyone! I am the proud new owner of a gorgeous little YM155D that has a couple of issues I hope to sort out. After getting her home, I noted that the seller was less than honest with me and did not tell me about the generator that doesn't charge and the temperature light that comes on after being run for a few minutes. I have an infrared thermometer gun that makes me feel that the tractor isn't actually getting that hot. 170-190ish near the engine outlet on the top hose and around 150ish near the engine inlet on the bottom radiator hose.

There's some manner of sending unit bolted into the head/block right behind the generator and right next to the outlet connection of the top radiator hose, but there's no wire attached to that sensor/sending unit. Is this the standard location for the sending unit/sensor on these little tractors? There's another sensor/sending unit almost directly below that near the bottom of the block and just forward of the oil filter on the same side. Is this the oil pressure switch?

Any information or guidance would be greatly appreciated.

 

[Aaron-HT]

The oil pressure switch is right near the oil filter (top picture). The temp switch is behind the generator (second picture) . I would strongly recommend adding a mechanical temp gauge instead of relying on that light.

Also be sure to read this
http://www.hoyetractor.com/overheating.htm

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[alan-HT]

Often when it won't charge, it's the voltage regulator, not the charger. A number of older posts explain how to tell, and you can use the Search box at upper right. It's a simple replacement but unless the new one (which will be solid-state and last forever) has the same number and color wires, find out what goes where before ordering.

Yes, you want to avoid overheating but the temp on an outer hose will be lower than that of the coolant around a cylinder. If too hot the usual things to check are the air passages, rad and fan, rad cap, and coolant mixture. Then you have to think of the head gasket, and there are lots of posts on that too.

Your model is an "export" one so factory documentation in English is available from any dealer with stock. There's the Operators Manual (came with new tractor), Service Manual (less than $100 and worth it) and Parts Manual.

 

[winston-HT]

Congratulations on your 155.

 

[astromarmot-HT]

Thank you to everyone for the replies!