what about the pressure switches in the AC lines? those switches tell the ac clutch to cycle on and off. thats what im referring to i sent you my number text me when you look at them and ill point out where they are if you have trouble finding them.

 

OK, I just wanted to update on this problem. I have checked everything I know to check on this thing and I am at a loss. I have checked both of the pressure switches. I even cut the wires going to the switches and replaced it with new wire, took the switch out of the dash and cleaned all the contacts, and I have had the computer in the truck refurbished again. I sent it back to A-1 Cardone with specific instructions for them to look at the AC. CJ360trider, I got your number and I will give you a call. I appreciate all the comments thus far. I just wanted to see if there is anything I am missing before I take it to a shop? Thanks!

 

I had a problem with mine,it was a vary dirty radiator(outside) causing the pressure switch to stop the clutch in the ac because of lack of air flow. I hope this dont sound stupid for you .As i read this you seemed to cover it all. It is all i can think of next to a bad clutch on the unit it self.

 

VP Dually, at this point, nothing seems stupid to me. I know it is something electrical. I have replaced the compressor, drier, and liquid line. So, I know it is something causing the clutch not to kick on and not the clutch itself. I have checked to make sure the condenser and the radiator is not clogged. I can manually ground it and make it come on but when it quits the computer removes the ground from the AC relay. According to the Chrysler FSM, if the truck overheats the computer will remove the ground. I know the truck has not overheated at all and the guage in the dash never reads over around 190 or so. But, could that sending unit be sending a different signal to the computer than it is sending to the dash? Any and all comments welcomed and appreciated!

 

your temp gauge sender and computer temp sender shud be 2 different sensors IIRC. and scanner will be needed to determine what the computer is seeing as far as engine temp goes

 

Sorry to dig up old threads, but I just thought I would update on this problem. The A/C went from intermittent to it just plain out didn't work. I got so flustered trying to work with the Chrysler wiring (PCM ground through computer) that I bypassed the PCM and have the switches manually cycling the compressor now with perfect results. The factory has the wiring going from the dash switch to the high pressure cut-off to the low pressure cycling switch to the computer. The computer then reads the pressures and "decides" when to send a ground signal to the A/C relay located in the power distribution box on the driver's side inner fender behind the battery. Evidently, there was some kind of screwy reading going to the PCM that threw its decision-making off course.

I rewired the system so that the signal goes from the dash switch to the high-pressure cut-off switch to the low pressure cycling switch straight to the relay in the distribution box. That signal works through ground (Chrysler switches everything through ground). Then, I ran a hot wire from an ignition wire to the other side of the relay. It is not hot when the key is off so as to not leave the compressor clutch engaged when the truck is shut off and the dash switch is in the A/C "engaged" mode. That is basically how the old systems worked prior to the advent of computer-operated A/C systems. I hooked my gauges up and, indeed, the system cycled just as it should. I even left the guages hooked up and drove up the road with them poking from underneath the hood to make sure it was cycling and not staying on continuously. Everything works as it should now!

 

I am having a similar problem win my A/C
efbeason can you post some pics please

 

sounds like you have a faulty ac control circuit in your PCM. Good to see you found a way to work around it and still have it be sensor controlled. a basic wiring diagram or pics would be neat to see