[Kevin]

In the past on my MY'03 the connectors for the fans have become corroded so perhaps worth investigating if you have similar connectors.

 

[Kevin]

Yes, true, the connectors are probably OK.

 

[Kevin]

Did you check the radiator thermofan switch(es)? on the radiator?

I'm putting it up on ramps today and I'll try to locate the sensors that were referred to in an earlier post.

The sensors referred to by karlaudi did not exist on either of my Subarus therefore I doubt very much they would be on your vehicle. The workshop manual for MY'03 (incls non-turbo and turbo) refers to just one "Engine Coolant Sensor". As well there is the "Intake Air Temp Sensor" and the "ATF Temp Sensor" but I cannot imagine either of these stopping the fans.

If the car needs to be used just run direct fused power to the fans with a switch under the hood. I did this as a temporary fix in the past.

 

[Kevin]

Yes, they did both come on Bobby.

I did the diagnostic test and the fans function.

It would be interesting to see if any old codes exist.

 

[Kevin]

Could be a thermostat issue. If you run the engine with the radiator cap off is there any evidence of flow and/or the coolant getting hot?

I'm pretty sure the heater connection is independent of the thermostat so it can get heat without coolant flowing through the thermostat.

 

[Kevin]

I always thought that if the heater worked that meant the cooling system was circulating the coolant well.

There is a heater bypass hose from the water pump so the heater can function without coolant flowing through the thermostat.

 

[Kevin]

Curious... if the coolant temperature is 160F, then that's too cool for the radiator fans to operate. In addition, at 160F how can the coolant gauge be showing hot, in the red?

Yes, confusing. I guess it depends from where the 160F reading is being taken?

 

[Kevin]

If the coolant gauge worked before the coolant temperature sensor was replaced, then that may be pointing to an incompatible aftermarket part.

If the 160F was taken from the OBDII port then I reckon Bobby has already nailed it.

 

[Kevin]

As pointed out, 160F will certainly not turn the fans on and would certainly not push a temp gauge into the red. For example my temp can go to about 220F (105C) and the gauge only goes about 3/4 of the way up but not into the red.

I guess we'll just leave it with you; good luck.