2003 Envoy AC stopped working

[Riktar]

Just got a call from my daughter that her AC stopped blowing cold air and that she smelled something like burning wires. When she got home, she popped the hood and checked that the compressor pulley was turning and it was. She also said the burning smell is going away. Is there a relay/switch that controls the engagement of the compressor that could have failed/fried?

 

[christo829]

Does it have the manual or digital HVAC controls? If manual, my bet is that the blower motor resistor
pack died...or the blower motor itself, or both. You can still have a similar failure with the digital controls,
but the failing component is an HFET inside the controls themselves, so it's less likely to noticeably cook off
and smell like the resistor modules, and just goes flaky.

If the accumulator tank and associated piping is cold, AC is generally working.

The quickest thing to look at first is the module and blower connector (and blower motor, since they can die
as well), under the passenger's side dash.

Do you have a multi-meter that you can use to test the voltage going to the blower?

If all that checks out, *then* start looking at the AC.

Good Luck!

Chris

 

[Mooseman]

Doesn't sound like a blower motor issue. If you mean it blows warm air, it could be the compressor clutch slipping. This would also cause the burning smell. If that's the case, it's usually caused by the aging electro magnet or the worn clutch increasing the gap. Usual fix for both is to remove the clutch shim.

 

[christo829]

Mmm...good point. I focused on the "stopped blowing" part, and not the more specific "stopped blowing cold air". Burning wires smell could have come from either.

Cheers-

Chris

 

[Riktar]

Yes, the fan controls are still functional. Just that it's now blowing warm/hot air. Thanks for all the suggestions. I will follow up once I get a look at it.

I should have better described the problem since after I read my initial post I can see where it could be interpreted as a non functional fan/blower....

 

[16vcabman]

Is the clutch locking on the compressor? You can look down and see if it is engaged.

 

[Riktar]

Well, I still have not had the chance to look at it. Work has been beyond crazy.

The Son-In-Law took it upon himself to just yank the whole compressor out and replace it.

So I get to avoid dirt under the fingernails. Yay me!!