Hello I'm trying to find the problem with the cooling fans in a 05 XLE. The fans do not turn on when the car is hot. The relays all work. When you turn on the AC both fans turn on but the one on the drivers side turns off after about 2-3 seconds. When using a power probe you can shoot 12 volts to the fan and it stays on as long as it has power fed to it. Is this possibly the temp sensor on the engine or the switch in the radiator? Any help would be appreciated.Thanks!

 

The coolant system has two temp on/off switches.

One is located on the radiator (has 2-wires, one white/black), the other on the engine coolant exit manifold (one blue wire). The switches open at 203F and 194F accordingly.

If you unplug the manifold switch the fans turn at one speed, if then unplug the radiator switch, fans turn faster.