Hello, I have a 99 Mitsubishi Diamante that I just replaced the compressor, expansion valve, and dryer in. The AC works great but the radiator fan won't work. I bypassed the thermosensor on the engine block and the fan works great (both) I replaced the sensor but still no joy. All relays check ok, fuses too. I can't locate the second sensor to check it. The engine does not overheat even with the fan not working. The condensor fan works only when the ac is on, otherwise no fans work. Thanks for any ideas!

 

Sorry, found out that the radiator fan actually works after I have run it and I let it sit for a few minutes. The radiator and condensor fan comes on and when the engine cools down, the radiator fan goes off. I thought that the radiator fan should run the whole time the AC is running to help cool the condensor but it doesn't. I will check the Hi speed windings to see if the motor has a bad Hi speed. The Ac works fine but better when I am in motion. Thanks

 

Ok, the fan has 2 harnesses, the larger one is for high fan. The smaller is for low speed and should have 12 volts only when the AC is running. The 12 volts are there but the fan is not running. Ordering a new fan motor tomorrow.

 

im having the same problem now the fan doesnt turn on the car doesnt over heat i have no idea what it is though

 

Turns out, my fan motor was bad. I replaced the motor and now all is well.

 

I Got it online from Pam's Auto for about 70.00. I installed it in about 30 minutes.

 

30minutes? impressive. It took me an hour to replace the radiator fan and the blower motor. Maybe I am really not that good at DIY stuff yet..

 

By the way, my blower motor recently went out, 2 days ago, easy fix, got the motor at Autozone for 65.00. I thought it was the ecu at first but was very happy that it wasn't.