cooling fan won't start

[rtr]

Just got my mini truck (92 hijet 660) and noticed the temperature gauge climbing way too high. I also noticed that the radiator fan was not starting. I hooked the fan up to a battery and it works fine so i think it could be the coolant temperature sensor. Does anyone know where the coolant temperature sensor is or if theis is even the problem.

[Mighty Milt]

i'm not sure where it is for your exact model, but past experience would lead me to look at the radiator or near the thermostat. they are typicaly small brass fittings with two wires connected to them.

if it's on the radiator and you have air in your system, or a stuck thermostat that is not allowing the water to flow the sensor may not know the system is overheating.

[rtr]

thanks for the info....you were right it was at the bottom of the rad. The plug was a little lose but the fan is working fine now. It is still running hot and I noticed an old thermostat in the glove box so I'm wondering if the guy I just bought it from was having problems too. Any thoughts?

[Mighty Milt]

if i were a betting man, i would pull the thermostat housing and guess what? you probably won't find a thermostat in there. a lot of misguided souls ahve erroneously come to the conclusion that removing the thermostat will make an engine run cooler. more than likely it seized up. to double check if it's working or not put it in a pot of water and slowly bring it to a boil. the thermostats open somewhere between 160* and 210* (not minitruck specific but a general rule). water boils at 212* if the thermostat doesn't open by the boiling point it's no good. if it does open at some point through the heating cycle i would reinstall it and see if it still runs hot.

something else to check would be your radiator hoses. have someone rev the engine once it reaches operating temperature and look under the truck to see if the lower hose is collapsing and robbing the radiator.