I think my E-fan is bad.
It does not turn when the A/C blows.
I read somewhere in this forum that it should run with the A/C.
Is that right?

And if that is so has anyone changed one out on a 4.7 [2002]?
Do I really have to remove the Radiator overflow and all that?
Any tricks?

 

Yes it should run with the A/C on... I would start by checking the relays and/or fuses to see if there bad first. IIRC, (and someone correct me if im wrong) there is a plug down under the truck near the fan i would unplug it and connect a volt meter to it and crank on the A/C and see if you have power to the fan. that will give you a good starting point.


Check out the FAQ's thread... IIRC, there is a DIY write up on that.... There is also a link to the 2002 service manual there.....

 

You can unplug the fan and run a hot wire (and a ground) to it to see if it kicks on. If it doesn't, it's toast.

 

yup it SHOULD go on with the A/C, if it doesnt start by checking fuses and relays(simply swap the relay with one of the same number) in the PDC (black box under the hood) and if they are all good do as samnbensdad said and see if the fan even turns, if it doesnt turn THEN replace it

 

I diagnosed my first fan by unplugging it and checking for voltage at the plug. If it has voltage, the fan is bad. If not, work your way back by checking for voltage at the relay. You can also try swapping out the relay next to it to see if that fixes the problem. On that note, I realized the fan I installed last summer is now dead. Has anyone had issues with Dorman fans? The fan blade moves front to back so either the bearings are toast or the mount is busted. I just ordered a replacement, should be here tomorrow.

 

Well to appease you all i checked voltage at the plug - no voltage.

I ran a hot wire to the fan - no turning.

So do i have two issues on the same item>

 

When you checked for voltage, was the key in the on position and a/c turned on?

 

actually the engine was running with the a/c on

 

i would guess the relay is bad and the fan (since it didnt start with a direct hot line)

 

Or a broken ground connection on the fan. When you checked for +12v at the connector did you check it between the wires or between the hot wire and a chassis ground point?

Check for an open circuit between the ground wire and a chassis ground point.

Just a thought.....

Bob