· Mr. Fixit
Chances are it's the fan controller. Somebody here can reveal more about than I can. My experience lies more the second generation Minivans....
Bob, I respectfully disagree. John Wood's post explains this problem very well, IMO. I believe that relay was engineered with a fail mode as "Always On". I'd rather hear the fans run than hear the engine seize.Then it has suffered electrical 'latchup' from the inductive kickback. Same solution, needs a diode to block the energy.
You should be able to check if it is the PCM by seeing if the fan relay is getting a trigger voltage with the van off, fuse in place and the fan running...or just pull the plug from the relay under the same conditions and check for voltage at the appropriate pin on the harness end of the plug. That way you won't have the fans running when you do the test.Thanks everyone....I took out the fuse to stop the fans last night. When I put it back in this morning the fans started up again. I have a cup of coffee, my serice manual open, and will pull that relay out today. Looks like I might have to wait until Tuesday to get parts unless the guys and NAPA have to work on Labor Day. I just hope it is not the Power Control Module....one of the possibilities the service manual suggests.
The vast majority of Chrysler products shut the fan off with the ignition off. I've never had one that behaved differently.So, is there no condition under which the fans should run with the switch off? Most other cars I own, the fans will run whether the ignition switch is on or off if the coolant temp is too high. My 2000 Grand Voyager, seems like they will only run with the ign sw "on".