Hi I've just changed the resistor on my polo as the fan wasn't working. Everything now is working but I'm getting an odour of burning from the air vents . Could this be just because its new or is it more likely the resistor is faulty?
Vw polo heater resistor
- Thread starter micpwelsh
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This isn't my area of expertise, so please ignore! 
But, it's as likely that the fault that caused the first resistor to fail, is also causing this one to fail. Because its brand new, it may take a fault load (and overheat) for longer than the old one did (which just went pop!).
So possibly a fault with the motor (excess currant draw)?
Otherwise it could be the wrong value or wattage of resistors (doubtful)?
Can you take it out easily and look for evidence of overheating?
Very unlikely, but there's a small chance that a protective coating had burnt off during first use?
You could also check the cabin filter isn't clogged, blocked air flow could lead to overheating.
As I said though, I could be very wrong!
But, it's as likely that the fault that caused the first resistor to fail, is also causing this one to fail. Because its brand new, it may take a fault load (and overheat) for longer than the old one did (which just went pop!).
So possibly a fault with the motor (excess currant draw)?
Otherwise it could be the wrong value or wattage of resistors (doubtful)?
Can you take it out easily and look for evidence of overheating?
Very unlikely, but there's a small chance that a protective coating had burnt off during first use?
You could also check the cabin filter isn't clogged, blocked air flow could lead to overheating.
As I said though, I could be very wrong!
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I’m not familiar with the Polo resistor but I know a common fault on Fiesta's were the pollen filter being blocked which slowed down the airflow through the heater. The resistor relied on that air flow to keep it cool. Maybe it’s that?
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That's what I think killed the first resistor. The pollen filter was covered in a blanket of fluffy stuff
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Correct, and the cause of the Zafira fires too. My car uses a thyristor speed control, cooled by the fans air flow. It's pollen filter became blocked which removed the cooling and the thyristor over heated and blew.
I would suggest the OP's smell is just the oil used in forming the resistor burning off with initial use - worry if the smell continues.
