radiator fan will not come on

[chriscw81]

hi everyone. hopefully someone can help me out. i have a 1996 3.8L and the fan on the radiator will not come on no matter how hot the car gets. the the thermostat seems to be working because the temperature guage works fine. i disconnected the power connection from the fan and ran battery power and ground straight to the fan and it did come on then. is there some kind of switch that the thermostat tells to turn on the fan when the car reaches a certain temp? if so, i'm hoping to replace it myself, ive got a baby coming and cant afford to pay to get it fixed. thanks in advance for any help.

chris

 

[wmburns]

Start first be checking all of the fuses. There is a FP panel in the engine bay and by the driver's kick panel (I/P). For the v6, there may be an additional small fuse panel on the right hand side.

Does the fan run when the AC is turned on? What happens when the engine temperature sensor is disconnected?

When the basics have been covered, it may be the CCRM.

 

[chriscw81]

well, ive checked all of the fuses(even checked them with a multimeter). the fan will will come on when the AC is turned on, and goes back off when the AC is turned off. someone else told me to see what happens when the temperature sensor is disconnected but i'm not sure where the temperature sensor is. is there somewhere online where i can find a picture that shows where the sensor is?

 

[chriscw81]

ok, i found the temp sensor. i disconnected it with no change. any other ideas? by the way, thanks for the help.

 

[wmburns]

How to trouble shoot V6 fan

The V6 uses a single speed fan. So the fact that the fan comes on when the AC is on says that the fuses are good and the CCRM is good. So that means we should concentrate on the temperature sensor. For the V8, disconnecting the temperature sensor should make the fan come on. Not positive what the V6 should do.

Inspect the wires to/from the temperature sensor. Look for cut/chaffed wires. Next use an ODB2 scanner to monitor the coolant temperature sensor. Is it reasonable?

How to diagnose a bad fan CCRM:

The CCRM is located in the passenger fender well. Accessible is tough. Best to remove the fender liner. Confirm there is power to BK/O wire (key on). If not, bad fan fuse (shame on you!).

Next ground out the DB wire. Confirm there is +12 volt to the R/O wire. If no power, the CCRM is BAD.

If power, there is a fault in the wiring back to the fan or the fan ground is bad.