Hey guys,
I just got a new issue with my truck. 2005 GMC 2500HD crew, 50k.
Ok, so we're driving in the truck this evening, I turn on the AC and all of a sudden we get the nasty stench of burning plastic going on really bad. I turned off the AC plus the entire HVAC system so it wasn't too bad for the ride home. Got home, popped the hood and ran the system on high. Nothing funny going on under the hood and no funny noises anywhere. Turned off the AC which still blows cold air and it still stinks bad. Cycled through all the vent locations, all work fine and stink the same. The blower is still pushing the normal amount of air on each level.

Any ideas on what has gone bad?

Thanks

 

Blower resistor is hitting the plastic? Its by the passenger foot area.

 

Thanks for the possible lead. I'll check that area out in the morning.

A friend mentioned that the AC filter might be clogged. I've never even looked for the AC filer on the truck. Do we have one that can be removed/cleaned?

 

No, but it just so happens the blower resistor is right in the same area.

 

Blower resistor and the electrical connector are melting very common problem take the connector lose and guarantee you will find melted pins and connector

 

Agree with everyone else, here is an article about install and removal in an envoy so you can get an idea on where it is and how to remove it to check ithttp://www.sparkys-answers.com/2009/...er-speeds.html

and here is one about the cabin air filter http://www.sparkys-answers.com/2009/...ing-cabin.html

 

Thanks for all the great info guys. I lowered the glove box and saw some wires there so I just moved them around a bit to see what would happen. Started the truck and the smell seems to be gone. Now the new issue... Blower motor works fine on settings 0-4 but 5 doesn't work now. AC works, heat works, cool air works, just not on setting 5. Is my blower motor failing or could it be the electrical connectors mentioned above.

 

The problem is in the wiring/connector/resistor area as mentioned, if it were the blower motor it would be bad on all speeds. The harness that goes to the blower resistor is known to melt...

 

Thanks, I'll take it apart next weekend and see how bad it looks. I'm traveling all this week so no time until then.

 

I have an 05' and had the exact same thing. connector had one loose connection and it melted the connector. Also had no #5 speed for the fan