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2013 Expedition main fan runs randomly for seconds
My fan will turn on and run for 5 to 60 seconds very randomly. This morning on a cold start, I backed out of the drive way and it turned on for 5 seconds, then in drive it turned on again for 5 seconds. Some days it will run while sitting in the drive-through making it difficult to order. On the freeway it will turn on, and you can feel the power drop. I've replaced the thermostat upon suggestion, but that didn't fix it. I got a fan relay switch from advance auto, but I don't think it's the right part as it doesn't resemble anything in the fusebox under the hood.
Took it into the dealership but they said they couldn't reproduce the problem (among several other issues).
When did this start happening?
Have you replaced anything other then the thermostat?
What is this fan relay switch you bought?
Have you been in a wreck? Ive seen two that had a ground wire damaged in the harness when they got in a wreck and the body shop didnt find it.
Unfortunately to track it down the issue other then just throwing parts at it you will need to be able to duplicate the problem on demand.
When did this start happening?
Have you replaced anything other then the thermostat?
What is this fan relay switch you bought?
Have you been in a wreck? Ive seen two that had a ground wire damaged in the harness when they got in a wreck and the body shop didnt find it.
Unfortunately to track it down the issue other then just throwing parts at it you will need to be able to duplicate the problem on demand.
We bought the car a year ago, it's been doing since the start, but didn't notice at first. No wrecks that we know about.
Ok here is the diagram for the cooling fan.
The wiring is fairly easy, PCM supplies a ground to the fan relays depending on which fan and speed it wants them to be on.
Since you want to know what is next to replace I guess it would be the relays and fuses. They are not that expensive and very easy to replace compared to the cooling fan, the relays are 5 pin relays and it will not work right with 4 pin relays.
I would look over the wiring harness in the engine bay for any chaffing or damage, I can also post connectors views so you can test the wires but that can be difficult since its a intermittent issue.
At least try to get it to act up once with the hood open so you can tell if both fans turn on or only one turns on.
Last edited by scott.butler4; Aug 24, 2020 at 03:55 PM.
2013 Expedition main fan runs randomly for seconds
