Cooling fan troubleshooting, could someone verify my tests

[rwhite]

95 contour at, zetec

Car seemed to be over heating and the fan would only cycle for a short time when the guage got to the "A" or "L". So with the ignition off:
1. I pulled the relays and jumped the black one labled "engine cooling fan" in the owners manual and the fan would run.

2. I then jumped the green relay and got nothing.

3. I left the jumper in the green relay and pulled the plug on the resistor and jumped that, the fan would run.

I'm guessing from the posts I have read on here that the resistor is bad? If someoe could verify this before I go buy parts I would appreciate it. It's my daughters car and she doesn't have alot of money to throw at parts.

 

[Lavell]

Believe it or not, this is a normal operation. The cooling fan kicks on at 212 degrees F, which is about the "M" or "A" on the temperature gauge. This is what's programmed into the PCM. I personally think that Ford was stupid to program the cooling fan to kick in so late. But like I said, this is normal.

 

[rwhite]

Isn't the fan supposed to come on if I jump the green relay? It's not coming on with the a/c on either, which I thought it was supposed to be on all the time.

 

[Lavell]

If the fan is not coming on with the A/C, now you have a problem. I would check to make sure the cooling fan assembly is working properly. Start at the electrical connector on the A/C compressor. Check to make sure that the connector isn't broken and that the wires are good. If that checks out okay, then go to the fuse box inside the engine bay and check relays R2 (black) and R5 (dark green) to make sure they're not broken. If the relays checks out okay, there is a resistor assembly located on the bottom left-hand corner of the cooling fan assembly. Check to make sure that resistor hasn't rusted out. If it is, replace it. If the resistor assembly checks out okay, then disconnect the main electrical connector on the cooling fan assembly and run 2 jumper wires, connecting them to the battery. If the fan doesn't come on, the fan is dead and you will have to replace the entire fan assembly.

 

[rwhite]

So based on the tests I did that I mentioned above what else do I need to test?

1. Should the fan come on when the green relay is jumped? There is power to the relay.

2. Does the fact that I jumped the resistor plug and green plug at the same time and the fan came on tell me anything?

 

[Lavell]

The answer is "no" to both of your questions. Your tests are inaccurate. The cooling fan comes on and off in 2 stages (low speed & high speed) by signals provided by the PCM. The PCM determines when the cooling fan comes on and goes off based on the signal it gets from the engine coolant temperature sensor. The black relay is the high speed signal booster and the green relay is the low speed signal booster. Having said that, the only way to test the fan for proper operation is to disconnect it from the PCM (main electrical connector on the cooling fan assembly) and provide direct power to it. Jumping relays won't work. You will need to perform the checks as I have outlined in my 2nd post of this thread.

After you perform the checks as outlined and everything checks out okay, then the problem lies in the engine coolant temperature sensor, the wiring or the PCM.