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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47281
Experience:  16 years experience
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2009 Ford: my entire engine fan with module..assembly..idling

Customer Question

I replaced my entire engine fan with module with a new assembly (2009 Ford Edge). The old fan would not come on when the engine was hot, causing the motor to over heat when idling. The new fan assembley won't turn off. After the engine is turned off it keeps running until the battery runs down. After charging battery I plug the fanback in the next morning before starting the car and it turned back on immediately. Is there a fan relay somewhere other than in the fan module on the fan assembly or could it be a defective heat sensor?? Any help is appreciated. It gas tow package.
Submitted: 5 years ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 5 years ago.
Hello, I'm Chris.

Sorry for the long delay, do you still need assistance?
Customer: replied 5 years ago.
Expert:  Chris (aka- Moose) replied 5 years ago.

There are no relays in this circuit. The PCm controls the cooling fan via sending a signal to the fan module. The wire shown in the diagram below is most likely chaffed and grounded and needs to be ohm tested to ground when disconnected at both ends. If the wire is fine then fault is internal inside the PCM.

graphic

Customer: replied 5 years ago.
Wire is ok so you mean the new fan module is bad or the PCM relay. The old fan wouldn't turn in the new won't turn off when I bypassed the old fan
module the fans turned
Expert:  Chris (aka- Moose) replied 5 years ago.
Since the wire is fine then the fault is the PCM is bad.
Customer: replied 5 years ago.
Is the PCM inside the fan control module? The white and blue line goes from the plug in the fan module to the harness the connects to the fuse box under the hood. I changed the PCM relay with a new one still no luck
Expert:  Chris (aka- Moose) replied 5 years ago.

Earlier I explained you need to unplug the connectors at both ends on the wire to be tested which is at the fan and PCM. The PCM is the vehicles computer. I assume you know where the PCM plugs in since you stated you did this test but just do not know where the actual PCM is located. Its sunk into the firewall on the passenger side of the engine compartment. See below

graphic

Customer: replied 5 years ago.
I the plugs both ends are easily accessable but the wires to the PCM goes directly under the fuse box looks like it wen into fuse box I did not know where the PCM was located I'll check where you said
Expert:  Chris (aka- Moose) replied 5 years ago.
OKay
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47281
Experience: 16 years experience
Chris (aka- Moose) and 3 other Ford Specialists are ready to help you
Customer: replied 5 years ago.
Ok I had un plugged the wire from another connection point unplugged wire at PCM and fan module and wire was ok. Tested for ground with both ends unplugged ok plugged PCM connector back and the fan connector end showed positive to ground is that ok or doesit indicate PCM bad. I appreciate yourhelp I'm trying to help daughter who lost teaching job by replacing parts dealer thougth was bad.
Expert:  Chris (aka- Moose) replied 5 years ago.
Since the wire ohm tested good this means its a fault inside the PCM since its the only thing to control the fan.
Customer: replied 5 years ago.

I took the vehicle into the shop so they could replace the PCM. When they tested the PCM they said it was OK and they rechecked the wire to make sure no ground. The diagnostics test said it was a bad fan module so I replaced the fan module again. Just finished and as soon as I plugged it in the fan started up. When I turned the ignition on the fan stopped. When I started the motor the fan came back on at a slow speed. When I turn off the car the fan starts up again slow and then turns on to high speed and won't stop??

Expert:  Chris (aka- Moose) replied 5 years ago.
All of this means its not a fan issue, and since 2 differnt eyes have now checked the wiring then its still the PCM at fault here.
Expert:  david craig replied 10 months ago.

here it is