I have a 01 grand caraban sport with a 3.3 and i have no power to the compressor. it was running good and the clutch in the compressor went out. so i replaced the compressor. now that that is done i have no power down to my compressor. i have checked all the wires and i have power to the fuse and the relay is good. i am thinkin it is the pcm from all i can gather of this. if any of you can help please help me out. thanks in advance.

 

did you have the system recharged?

 

yes its all charged to specs. i flushed the system and put a new expansion valve and drier in it also. i can jump it at the relay and make the compressor kick in so i am thinkin its the computer that is not making the ground on it. would you know any where around where i can get a used computer to put in it. i talked to a guy yesterday and a new pcm is 800 here. he said that dodge has the pcms coded so you can not get a used one. would you know anything about that?

 

The pcm looks at the sensors before it engages the compressor. Are you sure they are all reading correctly? Mighty expensive parts throw.

dodge pcm's have the vin programmed into them and if you have programmable key or theft alarm, that information is also stored. The vin can be reprogrammed but be careful, I have seen many many times where used computors did nothing but cause more problems.

 

There is a pressure transducer on passenger side in the engine compartment. somewhat above the drain pipe coming off the firewall. A bad one can deactivate compressor from turning on because the pcm is signaled that pressure in the system is high, when really it could be good, but a faulty transducer tells pcm othewise

transducer is a safety device.



The A/C refrigerant pressure sensor operates much like other 3-wire sensors. The PCM supplies a 5.0 volt reference to the sensor, pink/yellow wire going to transducer.

The sensor supplies a signal circuit to the PCM. As the A/C pressure increases or decreases, the resistance of the sensor changes and varies the amount of signal returning to the PCM.

The PCM monitors the A/C refrigerant pressure sensor signal circuit and can determine when the A/C pressure is too high or too low. The PCM disables the A/C compressor clutch and sets a DTC P0530 when the pressures are out of range (high or low) for a predetermined time. The PCM disables the A/C compressor in order to prevent A/C compressor damage.

I wonder, will this help? The transducer cost about 100 bucks, so make sure of price, unless you could buy at junk yard.

Question I have is? if you by passed fuse box and ran directly to compressor and it turned on, are you actually by passing the transducer by doing this. If you aren't then u would say transducer is working because compressor is going on. you did check fuses?

 

I finally took the caravan to the dodge dealer for a diagnostics and they told me the expansion valve or H block as Chrysler calls it, was the problem. They are charging me $147 for the part and $252 for the labor, freon, vaccum, dye and fix any leaks. Is that a good price? They said that the expansion valve was not letting the control panel start the clutch.

Thanks to everyone who has reply to my post.

 

yep, sounds about right

 

Cost is within reason. I had expansion valve replaced in rear of van which calls for removing trim. and recharing the system after evacuation. cost 175. but had it done at local guy.

 

That cost is pretty much right on.

 

I pick up the car today from the dealer and they did fix the problem, but they did not fix a leak. The notes on the paper work said that the sales adviser was suppose to inform me of the leak. He was also going to tell me to take the car to the person who originally replaced the compressor and the dryer to have him fix the leak. Why would I take the car back to someone who was not able to finish the work. That's why I went to the dealership. Before they started the work he said to me that the cost of the repair would include the dye etc... I asked if they would fix any leaks and he said yes. Whats your opinion on this? I am really upset that they did not mention the leak when they told me to pick up the car. Is it that hard to find the leak with the dye in the system and fix it? I am asking for too much? He is the one that said they would fix any leaks.