# Air-vents burning odor 2003 Caravan



## BobinOntario (Aug 3, 2010)

2003 Dodge Grand Caravan I get an electrical burning odor from the dashboard air vents for the first few minutes after turning on the blower, for any settings (independent) of temperture, AC, or cabin-air recirculation. The odor gradually disappears while running the blower, and it doesn't come back even if the blower is switched off and on again. It only reappears after the blower has been shut off with the vehicle parked for an hour or more. Tried replacing the blower speed-controlling resistor unit behind the glove box but no luck. My van is not equipped with an AC air-vent filter so it can't be a dirty or mouldy air filter. The odor started many months ago and has very gradually been getting stronger ever since. Any ideas on what might cause the odor?


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## Wrench97 (May 10, 2008)

Sure it's not antifreeze your smelling?
The only other thing in or near the vents would be the blower motor and I would tend to think it would have stopped working by now if it was putting out the odor.


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## BobinOntario (Aug 3, 2010)

To wrench97 - thanks, it may very well be antifreeze (I assume you mean engine coolant), leaking perhaps from the heater core. How do I confirm whether it is antifreeze - how difficult is it to get at the heater core and inspect for leaks?


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## Midnight Tech (Dec 31, 2001)

Usually if it's a leaky heater core the windshield will fog even in the summer...the scent will be almost like a "burnt candy" odor. Depending upon how the heater box is designed, you will probably have nice soggy carpets in the same area.


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## Wrench97 (May 10, 2008)

Do the windows fog especially the windshield fog up regularly?

Not sure how tough the heater core is on those, I've been away from cars too long, but you'll usually find coolant lose in the radiator and may see signs on the carpet or under the carpet on the right side.


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## BobinOntario (Aug 3, 2010)

My windshield doesn't really fog up in summer unless there is a heavy rainstorm, and the AC will usually defog it if it does. Haven't noticed any wet or damp areas on the floor carpeting under the dash, nor have I noticed greater than normal coolant loss from the refill tank in the engine bay, but I do recall it needed topping up at my last oil change service. Now that you mention it too, a "burnt candy" scent might be more accurate than describing it as a burning electrical odor. But it puzzles me still because it emits from all the front vents immediately on turning on the blower, long before the engine or its coolant has had time to heat up. Would leaking coolant in the heater core smell so badly right away I wonder before it has had time to heat up? Also, a co-worker at my office suggested it could possibly be overheating of the blower motor bearings, leading to melting of plastic or wiring insulation in the motor, perhaps dissipating after a few minutes as the air flow cools it down. In any case, can I narrow this problem down to a leaking heater core or a blower motor on its way out?


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## Wrench97 (May 10, 2008)

I think it's going to be a heater core starting to leak, the smell is from the vapors trapped in the AC/Heater system the coolant will lay in the core/heater box until the fan pressurizes it to blow it out.

If the blower motor was failing the bushings would have failed by now and since it's most likely under the hood in the engine compartment running would not cool it down by much.

Pressure test the cooling system and check the condensate tube for signs of coolant as well as the heater box seams and floor under the carpet while the system is under pressure, sometimes a small leak or a core leaking only when cold(engine not up to temp) as heat makes things expand and will at time make the leak stop.


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