Jllewan

Has anyone experienced the 2 cooling fans to constantly turn on a off over and over once the car get warmed up? I can be at a stop light or just turning the car off after a drive and the fans will turn on for like 15 seconds then turn off. It will do this until the engine temp is lowered. I'm wondering why they just don't stay on until the temp is ok?

V2Rocket

could be sign of a faulty fan switch or fan relay but they only run when the coolant temp in the radiator is above the fan switch's set temp. once temp falls below setting = fans turn off.

Jllewan

So what would you suggest I try first to test? Is there another relay that I can swap out? Thanks!

V2Rocket

what year is your car ?
85.5+ cars use a specialized (expensive) relay but you might find someone local who can lend you one. where are you located?

early cars (82-85, square dash) use a generic relay that can be swapped for any another.

931guru

Seen this before... There is a failure in one of the large ceramic resistors to drop the radiator fan speed down.

racerguy1

Another possibility... Your exact problem occurred on my 931 after a head gasket replacement and the wrong coolant thermostat was installed. The installed thermostat temperature rating was such that when the engine reached operating temperature the coolant temperature was slightly higher than the temperature necessary to activate the fan through its coolant temperature sensor. Don't know if you've replaced your thermostat recently but imagine also that an old worn thermostat may not be opening properly.

Jllewan

My car is 1988 and i'm located in Oshkosh WI.