Ok where do I start here? Bought this truck used Nov of 2011 175K miles. Put on an intake,4" straight exhaust,38R, Banks Transcommand and a TS performance 6 pos chip. Truck runs great... fast forward to I guess about 3 or 4 weeks ago I'm in my garage working on one of my mountain bikes and I notice my truck making clicking noises...I think to myself did I leave the damn keys in the ignition? My hand goes to my pocket and they are in it? So I go to my truck and check to see if the ignition is still on some how but no it isn't so I pop the hood. Something is clicking in the area of the fuse box under the hood and the clutch on the a/c is acting like the motor is running and it is cycling? I go inside the cab and turn off the A/C switch and it stops? I'm thinking WTF? is that about? I turn the A/C switch back to max and it does not start back clicking so I turn it back off and go back to what I was doing...now fast forward a couple of weeks and now the the truck starts acting funny...It starts right up cold or warm and then usually a few seconds later it dies? Starts right back up? It may or may not die again within a few seconds...this goes on a few days and progresses to it shuttering while driving down the road, then this progresses to dying and eventually to the point that I have to get it towed back to my Equipment Rental yard. I throw a few parts at it CPS, (doesn't change) IPC (No Change) IPR (no Change) Driver's side quarter mod(no change) and then finally pass side qtr mod( I removed all the battery cables and taped each side together to reset everything) without realizing it I have the A/C turned off after the pass side and it starts up and runs fine! I think Fing that was it! I drive it all the way home ...about 20 miles no shutter doesn't die nothing! I pull into my driveway and start reprogramming my radio...I think F-it it's hot let me turn on the A/C...you guessed it within a few seconds she dies...starts right back up but is loping and stuttering then dies? I turn off the A/C and she starts back up but is still acting kind of funny. So I do the battery cable reset trick again and now she runs fine? Also one other thing that has been going on is the little vac pump on the pass fender well runs constantly when ever the key is on? I'm gonna go by my tranny shop tomorrow and turn on the A/C get my guy there to scan it after it goes haywire again. Any Ideas on why the A/C would cause all the symtoms of UVCH problems, CPS, IPC or IPR problems?

 

I would start personally by unplugging the clutch, and then seeing if moving the A/C controls to on still does it, your compressor clutch could be so worn that it is shorting and dropping the voltage. That will help isolate if it's a clutch coil issue or other wiring.

Interesting issue for sure. If you have it hooked to the scanner while trying watch the voltage that the PCM sees too on the scanner.

 

Ok so my Trans guy is on vacation. So I went ahead and disconnected the plug to the compressor clutch and its full of oil, from the little bit of blow by from the dipstick(whole other issue with a BD CCV system) so I clean it out and spray it with a small shot of carb cleaner. I start the truck runs and idles...turn on the A/C contols to max a/c no problem so I plug the wiring for the compressor back in and it comes on and the a/c starts blowing cold and everything seems fine. I take it for a ride a couple of miles no issues? Could that motor oil in the connect have caused it to short out? I'm gonna drive it on some errands and see how it goes?

 

Interesting to say the least. As for the little pump you discribed is for our ac panel controls, 4x4 automatic locking hubs, exct. I'd say you have a leak in one of your hoses, either in the wheel well going to your hubs or behind the glove box, theres a junction of small pressure hoses that I believe activate your comfort control panel switches.

 

Ok I put over 80 miles on her today and no issues...no dying at idle or stuttering going down the road she didn't miss a beat! Back to her normal old self. I keep telling myself that part of this was due to the under the valve cover connections because both of them were partially disconnected. But who knows? I had purchased new valve cover gaskets back in Nov 2011 but didn't put them on. So since I already had them I put the new ones on and did the quarter mod while I was in there. And on that vacuum pump I did notice that eventually it does shut off. However if I pull the hose apart at the connection that goes to the A/C heater controls(my hubs are Manual only) and put my finger over the end coming from the reservoir it keeps on running so I'm thinking maybe the reservoir is where the problem is? But anyways thanks Big AL you sent me in the right direction.

 

Boy that is a funny thing. With it clicking and not running, and no key in who would of thought. Learn something every day

Chet