over a month ago, I noticed that the fan clutch engaged very erratically, and I had poor AC cooling at idle/low speeds. Checked codes with Edge CS. Found P0480. Changed fan clutch last week with a new Dorman model. Seemed ok for a few days, noticed AC was not better at idle. Now today, AC still poor at idle, and while slowly crusing thru town, I noticed truck with idle at 1000 RPM, no matter what I tried. I would shut if off, restart, and it would idle normal, but as soon as I started driving, it would go back to 1000 rpm idle. then it starts over heating. This truck has never over heated before. it was running 220-240 F. Got home, found nothing out of place.
Fan clutch will not engage at all now.
???????
Bad connection in new plug?
Bad wires some where?
Bad Crank sensor?

Very confused.

Thanks in advance for the help

 

If you are not pulling any air across the radiator and AC condenser is getting extremely hot, then I would be looking at fan clutch. Follow Chrysler diagnostic tests for P0480 maybe of some help

 

Ya. New fan clutch is not engaging any more. It free wheels all the time.
I'll test after work today.
Thanks