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Working on a 2000 Bonneville today. AC Compressor not working. Checked fuse and Relay and found both to be fine. Used external power source and compressor kicked in and ran. Checked for power at the plug with volt meter and had proper voltage there when ac was turned on at dash. The static pressure on my manifold gauges would not equalize so I wondered if my orifice tube may be clogged, so I evacuated the system, pulled the orifice tube and found it completely clean..... So I vacuumed the system, and attempted to refill with proper charge of refrigerant....because the compressor will not work I cannot charge to proper level outside of about 10-12 ounces that are sucked in from the vacuum on the lines..... this one is making me scratch my head....could I have a bad compressor even though it kicked in and ran with my external power source?? BTW, the condenser fan is not coming on when AC is called for..............

Place the refrigerant can (upright) in a container filled with hot water.

Tried that...but still can't get compressor to cut on.. I don't know if Compressor is bad, the pressure switch is bad, or the head unit is bad.....

To confirm you're only adding on the low side.

You said you could force the compressor to run with direct voltage, so just do that to get the prropper charge and then replace the pressure switch cause that is most likely your problem. If not it is the cheapest place to start tossing parts

It may be better to scan live data. The lack of condenser fan leads me to believe that the computer is not even commanding the compressor on for some reason.

RJolly87 wrote:It may be better to scan live data. The lack of condenser fan leads me to believe that the computer is not even commanding the compressor on for some reason.

I may be wrong and it wouldnt be the first time, but i think the fan is triggered by the compressor engaging and I think both are triggered by the pressure switch. I be it is the pressure switch failed

Do you have an stored codes? I had two high pressure switches go bad on me which left the AC system inoperative. Extremely easy to replace the sensor.

Goostoff wrote:

RJolly87 wrote:It may be better to scan live data. The lack of condenser fan leads me to believe that the computer is not even commanding the compressor on for some reason.

I may be wrong and it wouldnt be the first time, but i think the fan is triggered by the compressor engaging and I think both are triggered by the pressure switch. I be it is the pressure switch failed

It's my understanding that this generation uses a variable displacement compressor controlled by the PCM. PCM gets pressure data from both sides and pitches compressor accordingly based on conditions.

The PCM will typically throw codes too if it detects a problem and intentionally disables the compressor.

Tried a new pressure switch and no luck. I have no codes in regard to it either. I also forgot to mention that I did put a scanner an it and it's "calling" for AC to come on, but the compressor is not activating..... I also have power at the plug, tested it with a volt meter..... I'm just assuming I have a bad compressor at this time.

Does anyone have a schematic of the 2000 Bonneville AC circuit? This is driving me crazy.... Direct current works the compressor, I have power to the plug, I've checked the fuse and relay, a computer diagnostic is calling for the AC compressor to be enabled, a new pressure switch did not work...... I'm stumped.

I found the problem!! FINALLY..... it was a corroded wire, covered by the sheathing................of course the power wire was fine..... it was the signal wire.............