Burning plastic smell from vents.

[Bobbywolf]

When I turn the heat on high, I get a burnt plastic smell pretty bad. I'll be investigating this in a day or two, but I'd like any suggestions you may have as to what it could be before I dive into it. Only seems to do it on high with full blower.

Any ideas?

[93 Freshcort]

Does the smell continue or does it eventually go away?

[Davescort97]

Check the electrical terminals for the blower motor. Just to the left of the motor are the resistors to get the lower speeds. Check them, too, for burned or melted plastic on the wire harness. The recirculation for the heater is located just above the right kick panel. It's about a foot from the blower motor so it's no surprise you're smelling burned plastic.

[Bobbywolf]

Originally Posted by Davescort97

Check the electrical terminals for the blower motor. Just to the left of the motor are the resistors to get the lower speeds. Check them, too, for burned or melted plastic on the wire harness. The recirculation for the heater is located just above the right kick panel. It's about a foot from the blower motor so it's no surprise you're smelling burned plastic.

The connector that plugs into the blower motor was somewhat corroded, and I cleaned it up. Still have the smell. Sometimes does it on 3 & 4 blower setting. I'm also getting very little heat (with a new thermostat) but that may be an unrelated problem. I kinda put this problem off because it has been so mild, but now I need my heat again. Dropping down to single digits regularly in the last few weeks.

Also, the smell continues, and gets much worse to the point where it hurts my nose. I usually turn the fan down as soon as I smell a hint of the burnt plastic smell. The blower doesn't blow as hard as I remembered it did, so maby it is on its way out & overheating.

[dougand3]

"The blower doesn't blow as hard as I remembered it did, so maby it is on its way out & overheating."

That makes the most sense...if smell is coming out the vents, then smell is in the air stream. If it was hot wires or hot resistor pack, I think you'd get just a general diffuse smell.

You can pull the blower motor and check for smell. You may be able to clean and lube it but I doubt it. A new blower motor is ~$50 at rockauto or ~$56 at autozone.

[Bobbywolf]

Well, I priced a blower motor, and the cheapest aftermarket one I could get was $109. It ended up not being the problem anyways. After I pulled it, I hooked up my battery charger to the fan directly and put it on activate. The fan spins super fast and blows tons of air. I know that the fan wasn't the problem. I pulled out the harness/pigtail for the fan (3 connectors and interconnecting wiring) and all the connectors were corroded. I pulled the blower resistor as well. I sanded and cleaned all contacts by pulling them from the connectors, and took a small emory board and sanded in between the contacts. I used some dielectric grease to prevent future corrosion, put it all back togeather, and voila! All fixed. Blows like the day I got it, and no burning smell.

The burning smell ended up being one of the connectors melting down. The metal contact was still in decent shape, but the plastic portion is somewhat deformed. Everything is making good contact now, so that problem is fixed.

Now onto my lack of heat problem...(see other thread started by me)