Radiator Fan & A/C Quit Working

[crennie]

Originally Posted by mpe235

The ecm is covered for 8 years or 80,000 miles. The a/c problem could be a wiring issue. It is very common on this model. It is very common to find corroded wires in the harness at the lower radiator support. The 3 most common wires that I see are power to the Horn, A/c and ECM.

My girlfriend has an '02 Sentra GXE 1.8. The Radiator Fan quit working. I checked fuses - all ok. Tested Fan Relay - ok. Jumped Fan Relay and Fan works. Changed Coolant Temp Switch - still not working.

Sounds like ECM is either not getting the input signal to control (ground) the relay or the control signal isn't reaching the relay. Also, I don't know if this is related but the A/C hasn't worked in about 2 years. The car was taken to a mechanic for the A/C problem who diagnosed a computer problem.

Any ideas or help would be greatly appreciated.

[NissanTech]

I don't know if this is related but the A/C hasn't worked in about 2 years. The car was taken to a mechanic for the A/C problem who diagnosed a computer problem.

It should affect, but you can used it to test the system, because is a direct signal to the ECM to turn the fan ON. Without the A/C you need to meet all the conditions to turn the fan ON.

Most likely the problem is the ECM, but if you like to do more tests, the information is in the "Engine Control" section of the service manual. You can download the section free from here: Knowledgebase - 2002 Sentra - Nissanhelp.com page 1451