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This morning I was driving to work with the A/C on. After about five minutes I start to smell something burning then my center vent emits a grey smoke. I quickly turn off the HVAC fan and A/C. About three hours later I run the A/C again I hear a relay click but no cold air the HVAC fan works. I checked the sight glass on the dryer and don't see anything bubbling. I have noticed during the summer that the A/C was not cooling as well as it had in the past. Last night the HVAC fan blew the fuse but I don't see how that is related. What could cause the grey smoke from the vent?
Might be a good idea to look at your AC clutch. If the rubber's still supple and not cracking, that should be good (at least according to my local AC guy).
I plan on evacuating the system this weekend using the guides from Wally,Tails and John Pirtle. I'm just concerned with that burned smoke smell it was not coming from the engine compartment but the vents inside the car. When I checked under the hood I could not smell anything burnt. Could it be oil from the compressor because of lack of freon or a bad component in the HVAC ducting system.
The car has front and rear A/C from what I can tell that means 2.0 lbs does that sound right.
Last edited by shadowknight; Oct 14, 2010 at 04:04 PM.
Reason: updated
Maybe the pcb relay for the A/C that lives inside the hvac controller has burnt out? It's actually under-rated for the clutch draw so a common failure.
If you follow the guides you can trace the voltage for the clutch all the way from the controller through the freeze switch, low pressure switch to the clutch. That will tell you what's failed.
You can also jump power to the compressor clutch to check it pulls in and compressor turns.
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