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Discussion Starter · #22 ·
It's a PTC; Positive temperature coefficient. The colder it gets, the more current flows through it.
But the wiring diagram shows the part is an on/off switch instead of a variable resistance device.
Also, a PTC can fail shorted and cause fire at the heaters under the plastic combustible air vent.
 

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But the wiring diagram shows the part is an on/off switch instead of a variable resistance device.
Also, a PTC can fail shorted and cause fire at the heaters under the plastic combustible air vent.
Could........
BMW has been using the PTC for heated washer jets since the E23. I (for one) haven't seen it be a cause of any fire.
 
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