Oil cooler fan

[Nick Danger]

I have a 1989 370 LE MH with a Ford 460. There is an oil cooler fan attached to the radiator on the passenger side. It is fed by a black ground wire and a blue battery wire that I assume is connected to a sensor or sending unit on the block. Can anyone enlighten me as to when this fan should turn on? I've disconnected the circuit and tested the fan with straight 12 volts and it works, but I never see it working after the engine is at operating temp. I am guessing that there is a temperature threshold that must be met. My coach runs at 215 on the road.

Any help is appreciated.

Nick Danger, Third Eye

[Tinsel Loaf]

215 degrees is hot enough to turn on the cooling fan. Check the thermostat to see if it is working properly. The thermostat most likely shorts to ground completing the circuit turning on the fan. Pull the thermostat and check it for a buildup of crud which would make it not open and close properly.