I did a search but didn't find exactly what I was looking for. Here's the back story:

I was driving to work the other day and my "check gauges" light came on. Sure enough, my alternator wasn't charging. I drove another 30 miles or so and my AC quit cooling. I figured they were related somehow.
I pulled the alternator and took it to be tested. Sure enough it was bad. I installed the new one and it started charging normally but the AC still didn't work. I then installed a new AC pressure switch. Still didn't work. I then pulled the connector to the compressor and checked it for 12 volts. Sure enough, I had 12 volts to the compressor. I shut off the AC and checked it again. Still had 12 volts even with the AC and fan control switch off.
I pulled the codes and they showed the following:

0713(trans fluid high), 0483(cooling fan speed),2502(charge syst. error) and 0622(gen field not switching)

I figured with the 0483 code, something in the fan clutch was causing the constant 12 volts to the AC compressor which I assumed burned the coil up.
I installed a new AC compressor and a new fan clutch. When I went to install the compressor, I noticed the AC system was empty(keep in mind it was working great until a little after the alternator quit). It barely hissed when I hooked up my gauges. I figured being I had a constant 12 volts to the compressor that it must have pushed all the refrigerant out while I had it turned off(don't know if that's possible).

I pulled the system down and left it for over an hour. The gauges showed it to be holding fine. I was able to get one can of 134 in the system but the compressor still doesn't come on so I can't put more. I have not checked for 12 volts at the compressor again since changing the fan clutch.

I'm at a loss now. I have checked every connection I can find and wiggled the wiring in case of a bad wire somewhere.

Does this sound like a TIPM issue possibly? If so, is the dealer the only one who can reset that?

If anybody has any insight, I'm all ears.

Thanks
Dave

 

You need to know if you are getting power to the compressor clutch first, the trace it backwards if not. The switch in the dash tells the computer to turn on power to AC clutch. The power goes to a low pressure switch on the low side of the system. If pressure is too low, ~20 or less in most cases, the switch is open. Whatever R134 you put in should be enough for it to cycle for some amount of time, even if it's very short. If the switch is bad it will also be open. Bad connections or wires are also possible faults. You just have to methodically check up the line until you get to the computer or dash switch.
do not forget to look for a fuse to be involved between the computer and the low pressure switch. I don't know where it would be, under hood or under dash.

Chris