What controls the primary coolant fan relay?
I replaced the temperature sensor, and the relay but the primary fan (driver's side) never comes on even when the engine is hot.
If I select the air conditioner, the secondary fan (passenger side) comes on. I can run the primary fan by jumpering the relay contacts so I know the fan motor works. Without the AC on, the secondary fan is the only fan that turns on as the engine gets warm. If I disconnect the temperature sensor both the primary and secondary fans come on so the connection from the control module must be good. Is there another sensor in the primary fan loop?