Weird Electrical Problems - AC blower runs when truck is off

[JStankus]

I am getting some weird electrical problems with my truck lately.



The oddest of the bunch is occasionally I will come back to the truck and the Air conditioning blower is running when I get into the cab. Seems to do this more on really hot days (it was 104 today in San Antonio). No key in the ignition or anything. I am pretty sure the fan was not running when I shut down to go in to the store (actually today it was the Cummins Parts counter for air filters). Anyone see anything like this? Is some controller wigging out?



Some of the other electrical problems I am having:



Engine cooling fan clutch does not seem to engage randomly. I am trying to dig through the wiring to find where the wires rub and check them. I saw a thread on this a while ago and can't seem to find it. Is the rub point at the wire tie-off as it routes away from the radiator? (yes I did check that the wiring to the clutch was intact)



Passenger power windows intermittantly locked out.



Broken map lap (passenger side). The switch plastic seems to have broken. Counterman at the (now defunct) dealer said I had to buy the whole console for the parts.



Very poor AM reception--> which I think is from the dealer doing the blend door repair and messing up the radio antenna connector.



The ones I am most concerned about are the AC blower and the cooling fan clutch, but wanted to give the full electrical issues in case there is some root cause.



The truck is a 2003 QC 2WD pretty much stock with about 101,500 miles on it.



Thanks for the help





John

 

[10-9jc]

Things like that will be happening to all of us now.

Little Fiat Gremlins have infested your truck!

If you listen carefully, you will hear them chanting:
Fix It Again Tony, Fix It Again Tony, Fix it . . . . . .
(they don't care if your name is John)

~

 

[BarryG]

I really cant speak to most of your issues except you got some wierd stuff happening and good luck finding the root cause. In regards to the map light. I could swear I bought just a light assembly several years ago as my pass side one did the same thing. I know I didnt buy a whole new console but perhaps once I took it apart I fixed the one that was there but again thinking I bought a new one.

 

[Skydiver]

-Next time it is running try pulling the blower fuse. Make sure to pull the blower motor fuse, because if some wires are rubbing the fan might be getting its power from an adj. fuse from another wire.

-Next, have you installed anything new (electrical) to the truck where the ground may have been installed incorrectly? ANYTHING at all?

-Are there and rodents in your area? They love plastic.

-Does your cooling fan clutch have any wires leading to it?

 

[JStankus]

The last new electrical install on the truck was when it was new, my father in-law installed a trailer brake controller, but if I recall correctly that just plugged into the harness. Anyway that was over 100K miles ago



Nothing to indicate rodents around the truck. The local hawk is pretty good about keeping even the squirrel population down.



I did check the fan clutch wiring, which is all intact. I need to dig into the wire loom, since I recall someone on the forum having had the wires in the loom rub together and short. On my truck the fan clutch is intermittant, sometimes it works (i. e. cold AC at idle and low speeds) and some times it doesn't (misery at idle)



Regards



John

2003 QC 2500 2WD

 

[rjones]

Check the harness going to the steering column there's a black distribution box "multiwitch". . the harness was made too short for the tilt wheel and pulls out the harness from the box and gets hot ,Mine melted but had similar symptoms except not only the blower motor acting weird but wipers, gauges, turn signals left making right go on ,and lots of smoke from the burning wires... ... I hear Dodge knew about this but will not fix under any TSB or recall I rigged mine up at the time because I was away on vacation but its starting to act up again... ... I don't want to spend the money for the dealer to fix...

 

[JStankus]

Two and a half out of five ain't bad

Two years (40,000 miles) later and I finally fixed another one of the problems (I hope). Found on some of the other forums for Dodge trucks the ignition switch is undersized to carry the current of the AC blower and overheats the two upper contacts. Switched out the ignition switch. The one I pulled had some evidence of overheating. Not a bad job other than it pushing 100 in Texas and figuring out how to get the tilt wheel lever off to remove the shroud. FYI pull the tilt lever towards the steering wheel and it pops off easily (at least on my 2003 other years may vary). So hopefully, the blower will not run on after the ignition switch is turned off.



Fixed the passenger window lockout problem with a new switch panel for the drivers door from Dodge over the winter.



The cooling fan clutch is still a bit intermittant. (thats the half :-laf) I think it is a bad electrical connection in the connectors between the fan and the ecu (or in the harness itself). Unplugging and replugging the connectors a couple times reduces the frequency of the problem, though it is sometimes hard to tell. Would one of the OBD II scan tools that does real-time data like the Equus 3160 or Auto-tap be able to monitor the Fan clutch state?



AM reception is still weak. (not too big of deal)



Map light switch is patched together but not what I would call a robust repair. Anyone know a source for those dang switches?



John

2003 QC 2WD 142,000 miles

 

[Prairie Dog]

I can't help you with most of that but the power window thing is a seperate issue and the problem is discussed here: https://www.turbodieselregister.com/forums/3rd-generation-ram-forum-no-engine-transmission-discussions/230916-power-windows-inoperative.html

 

[JStankus]

I know I resurrected an old thread (my old thread on my electrical problems) but I was trying to indicate that I had about half the problems fixed.



FIXED - Blower fan running after key off. Fix was replacing ignition switch yesterday.



FIXED - Passenger power window not working. Fix was replacing drivers window switch panel this past winter.



Sort of FIXED - Cooling fan clutch (Code P0480) and poor AC performance in traffic. Maybe fix was reseating the connectors in the harness a couple of times. Though last night driving the truck after the ignition switch replacement I did hear more of the fan roar. I will have to check the schematics to see if a high resistance in the power feed to the fan stuff could cause the issue.



NOT FIXED (root cause unknown) - poor AM radio reception



Patched (but not a robust fix) - Broken map light switch. Patch is a zip tie holding the switch together. Need to find replacement switch or some epoxy.



John

2003 QC 2WD 142,000 miles

 

[rbattelle]

Regarding the fan, did you check the wiring harness where it enters the radiator shroud on the lower passenger-side corner? Very common to have that rub either the wires, the radiator, or both, causing shorts.

-Ryan

 

[JStankus]

The fan clutch is apparently is still not working since crawling through 10 mph traffic the temperature rose to the high end of the gauge. And then going up a mountain (not loaded only 4 people in truck) in Colorado, temperature was getting pretty hot. Coming back down it got to below where the temperature normally is. On the level and moving reasonably the temp was midscale. (half a needle width below the midline).



I checked the wires back when this started a ways back. I'll need to check that again to see if there is a more visible failure. Any parti cular areas as most problematic going into the shroud. Are there electrical tests I can do? What resistance should I see through the clutch?



Thanks for the help



John

 

[Wagon]

On my 06 every once in a while the interior lights will go out right away instead of fading out and then I clean the grounds on the fenders and batteries and its back to normal so maybe try that?