Farrell91

Hello, I was hoping someone to help me figure out the issues I'm having with my truck, which just ran out of warranty.

So to start this off, the outside temp is 2 degrees Celsius, which is 35 degrees Fahrenheit.

I drove my truck to work yesterday morning and it was fine, 12 hours later when I was walking to my truck, which i remote started, I could hear the cooling fans roaring away, way louder than I have heard before. I put the key in, turned the key on then back off and the fan shut off. I started it again with the key and the fans kept going at turbo speed. I drove it home anyways and the fans roared the whole way(1 hour drive), until I shut it off in my driveway.

I tried disconnecting the battery to see if that would do anything. It didn't. I drove it to work again this, same thing. I checked it out a bit more tonight, upon looking at it more, the rad has 2 electric fans. When I start the truck they both run for about 5 seconds normally, then the passenger side fan shuts off and the driver side one goes into warp speed until you shut the truck off again. I checked relay #5(high fan speed) and number #85(low fan speed). I checked them by putting them in the rear defrost relay(same type of relay) and engaging them, the light for rear defrost came on in the cab so I assume they were good.

Then I took out both high and low fan speed relays and the fan didn't run. But with even just one of them in it goes into turbo mode until the trucks shut off again....

So.... any ideas?

greasyknuckles

something is telling pcm to run the fan to run whether it is a temp sensor, the heater control telling it the a/c is on, a short to power or ground or even a failed pcm.
without a workshop manual and a scan tool that will monitor parameter Id's you
probably are going to have to take it in.

Phyer Phyter

Your cooling fans will come on with your defroster. Maybe you just haven't noticed this before? Even if your a/c defrost is turned off at the controls some trucks have an auto setting that will turn on heat or a/c depending on outside temp when remote start is used.

Feathermerchant

At low outdoor temps, the fans may run when the truck is stopped to prevent water vapor (from ice/snow melt) from steaming up. When moving they will shut down.

If you have low coolant, they may run also. Check your coolant level.

Cj7jeepoffroad

I'm having the same issue, have you resolved it?

jojofera

I have a 2013 Ford F150 off road and my fan runs too was fine all summer now it is winter and it runs for along time. very loud

Farrell91

Hey, sorry about the delay, all the emails go to my junk email. I did get it resolved. For now anyways. From my knowledge and some research, there are 2 electric fans. One of them is for the ac condensor. And apparently the fan is not ran off a temp sensor, but a pressure sensor. So when your ac system hits a certain pressure it kicks the fan in.

I have no idea what happened to my ac system, but the system pressure was low. I took it to a shop, they drained the ac system, leak tested it and found no leaks, then recharged it and the issue went away. So I'm hoping it doesn't happen again, but time will tell.

jojofera

Thanks my fan runs even when I don't have the the air on or heat. It is so loud. It is going in on Dec. 6th. I will let you know. Thanks for your help.

Cj7jeepoffroad

I found my issue: https://www.f150forum.com/f38/2013-f...nually-364732/