Is there anyway to test clutch/compressor in a canbus A/C system?

Thanks Joe.

So, I take it there's no trigger wire among those tiny com wires going into the clutch/compressor? I've seen people saying there is one, but running current into a wire connected to the ecm(s) seems like a bad idea unless I know absolutely.

I thought about the coil being shorted. Really, it's the only thing likely to keep the magnet from working assuming there's power. I put an ammeter on the ground strap. I can see it change when the door is opened or the radio is turned on, etc. Kind of cool actually, it draws a few to a few hundred milliamps with the key off and out. Normal I know, but the fluctuation is interesting. What's it doing when it flickers to 1/4 of an amp for a 10th of a second every hour or so? Anyway, pushing the A/C button shows no draw at all. And it's not the button! Haaaa. The clutch doesn't engage with the defroster on either. So, either the coil isn't getting power or there's a break in the coil winding. If it is shorted, it would use some power when on, even if it isn't conducting high enough current to create enough magnetic force to engage the clutch. It's more likely it's not getting power since the chances of the coil wire breaking and not shorting are pretty low. So, it's high or low pressure, a bad high or low pressure switch, or some other limit issue in the ecm. It would be nice, if the computer is controlling the A/C function, that they would enable it to record/report A/C OBD fault codes!

So, it looks like dumping the refrigerant, vacuuming it down and weighing in new 134a is the easiest thing to do before I start throwing parts at it.

Just to check before doing that, any idea what the pressure should be at say 82f ambient without the compressor running?

Just as an afterthought, I just now happened to think that I replaced the cabin blower in January because the bearings failed and the squirrel cage crashed into the housing. It blew the fuse. Could that possibly have anything to do with it? Sounds crazy, but so is a 'car area network' that controls stuff beyond the electronic entertainment/security system. Is this pain really worth saving a pound of copper? Dumb question, obviously it's worth it to Chrysler.

Thanks.

Thanks again Joe! I will check the pressure again ASAP, I'm remembering it being mid-sixties(!) Temperature should be low 80's after sunset and an hour or two to cool the vehicle. I'll check and top it off, if that's the case. I'll check for power on the dark blue/yellow wire and ground continuity if low pressure isn't the issue.

Either way, I really appreciate your time. I've searched for a legitimate pin-out for the clutch/compressor and not found it after hours of research. Might have seen your schematic and not paid attention, but I don't think so.

I'll report back with results.

Thanks so much man.