Tracking the dreaded AC problem - where to start?

packfan88 · Post by **packfan88** » Sat Apr 13, 2013 6:50 pm

So my AC doesnt work. Well, it doesnt get cold. the fan works vi athe control knob but it never gets cold.

I can spint he compressor clutch freely.

I switched the horn relay with the ac compressor relay and they both work.

Fuses are all good.

So i took off the connector for the compressor to strat to track back the voltage to see if its getting lost some place. Im not getting any voltage at the connector to the compressor. This is the 2002 with the wires colored blue/black and just black.

I have the book with the wiring diagram so I guess I dont need that persay. I just dont know the route to go to track this from start to finish.

I have no knowledge of this car prior to just buying it and it not working. No last known working date.

I pushed the fill valve to see if it even has some pressure and it does. I am going to get some freon and see if that is the problem. if it doesnt change anything, whats the steps to isolate the problem?

mopar2 · Post by **mopar2** » Sat Apr 13, 2013 8:44 pm

First run the vehicle and turn on the A/C, does the clutch cycle? Yes, check freon level, if your not equipped with tools take it to a shop. If the clutch does not cycle it could be low freon or bad clutch. If you've never worked on A/C I recommend a shop so that they can remove freon if necessary.

gtxtreme19 · Post by **gtxtreme19** » Sat Apr 13, 2013 8:48 pm

mopar2 wrote:First run the vehicle and turn on the A/C, does the clutch cycle? Yes, check freon level, if your not equipped with tools take it to a shop. If the clutch does not cycle it could be low freon or bad clutch. If you've never worked on A/C I recommend a shop so that they can remove freon if necessary.

This^
odds are it isn't a wiring problem, but a leak in the system. I could be wrong I have been before.

packfan88 · Post by **packfan88** » Sun Apr 14, 2013 6:24 pm

clutch not engaging. Its not locked up cause i can freely spin it by hand.

i have some freon but it only took a little bit to get it up to full.

Is there a was to force the clutch to engage and bypass everything else in the system?

packfan88 · Post by **packfan88** » Mon Apr 15, 2013 5:16 pm

So if no voltage at the connector on the compressor the path back is to the relay correct? The book has it to a diode first then the relay but on the side of the relay it has a diagram as if the diode is built into the relay. Is that how it works? 30 87 86 85 87a which should have voltage?

Post by **occasional demons** » Mon Apr 15, 2013 6:09 pm

85/86 is the relay coil. One of those will have fused power from fuse 10 in the fuse box. The other is grounded via the PCM to control the relay.

30 should have power also, tho I don't think it is keyed (switched) power. 30 to 87 is the switch that the relay makes to power the compressor clutch.

viewtopic.php?t=31396

packfan88 · Post by **packfan88** » Mon Apr 15, 2013 6:21 pm

so in theory if i jump 30 to 87 it should be a direct line to the compressor and power it up as long as the knob is turned to A/C?

Also, is there a way to change a compressor clutch on the car or it has to come out to do so. Is it even worth it/possible to fix the clutch or just buy one used on ebay for $50 with a 6 month warranty?

Post by **occasional demons** » Mon Apr 15, 2013 6:31 pm

If you jump it, the compressor clutch will engage, provided it's coil is good, whether the A/C switch is on or not. you are bypassing everything.

i have some freon but it only took a little bit to get it up to full.

If the compressor was not running, you cannot actually add refrigerant completely, but it should give it enough pressure to make the compressor run.

You may be able to change the clutch, if it is the problem, on the car. If the coil is bad, or the actual friction surfaces, you have to replace it. It is not repairable.