Chrysler Repair: 06 van: a/c wont cool - compressor will not engage clutch, powertrain control module, 2006 grand caravan

Question
QUESTION: last year spent money to have a/c redone by chrysler. this year only blows hot air. purchasd and installed 1 can of r134 no results. clutch will not engage. pressure on low side reads off the chart. swapped relays to check and fuse are ok. what shoul I do next? bleed the extra pressure off and reload low side to correct level. or is the pressure high because th eclutch will no activate. how do I tes the Clust?

ANSWER: It sounds like you have a pre-94 but I can't be sure which model. I don't believe these model years had a too high pressure cut off switch so that is probably not why it won't come on. Let me know the year/model/engine so I can check over the circuit. Do you have a volt-ohm meter to do some testing?
Roland

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QUESTION: sorry i forgot to list the make of the van. chrysler 2006 grand caravan es  3.8 litre........clutch would not come on before I add the r134 either

Answer
Hi Chris,
My most recent manual is an '02, but it probably applies to your '06. If the compressor didn't engage before you added the refrigerant, and it now appears to be too high and it still won't engage, then I suspect the problem is not the pressure in the system.
You could check the comressor clutch be briefly jumping 12V to the dark blue/yellow wire at the clutch and verify that is will work. If not, then verify that the black/gray wire of the clutch is grounded (or jump it to ground, and then re-try 12v to the dark blue/yellow). It if works, then check what is happening at pin 64 of the powertrain control module which is what controls the clutch relay. As it sits with the ignition 'on' it should show 12v, then when you ask for AC then it should drop to 0v, if it were asking the relay to close and thus activate the clutch relay. If it doesn't drop to 0v, then the pressure sensor signal or supply voltage may be not giving the pcm the ok to activate the relay. Find the a/c pressure sensor (which appears to be at the front/top of the engine near the throttle body) and verify that it has 5v on the pink/yellow wire, and that with the ignition 'on' there is some voltage between the 0 and 5v neasuring between the other two wires (which are the signal and signal ground wires).
Let me know what you find and we'll go from there.
Roland