a/c smoking in cab

[hiebs]

started my a/c today and smelled "electric" burning , then smoke began coming into cab. no smoke with vent on, only when the a/c is engaged. no smoke in engine compartment
Any ideas???

 

[dirtclod]

When you say no smoke on vent only, is the fan on or off?

 

[GMC Customer Service]

I’m sorry to hear about what happened with your Sierra! Are you going to try and fix this on your own? Has this been a recurring issue?

Thanks,
Laura
GMC Customer Service

 

[Bill325]

I've seen a thick fog coming from AC vents, which usually happens just before the AC evaporator ices up . It doesn't smell like anything burning, however.

 

[dirtclod]

I had a Toyota truck pump smoke into the cab on 2 occasions. The first time was during a rain storm and a cool fog of vapor exited the vents for about 5 seconds. I don't know why, but nothing ever became of it. The 2nd time, I smelled and saw smoke. It was caused by leaves that had entered through the windshield cowling and ending up in the heater coil compartment. The heater coil compartment also housed the fan speed resistor coil (wire gets hot when low or medium fan speed is on) and that's what ignited the dry leaves. Disassembled the heater coil housing, cleaned it out, and problem solved. Are any of these symptoms similar to yours?