my fan only runs on low, when the car is started it will momentarily run on high but then cut down to low. The car has auto climate control.
- posted
9 years ago
does a 99 avalon with automatic climate control have a blower motor fan resistor
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- posted
9 years ago
"Bill G" wrote in message news:ddd7f$542c4558$41b57997$ snipped-for-privacy@news.flashnewsgroups.com...
Yes, the car has a final stage resistor. The typical failure mode for this item is that the fan speed is off or HI. I do not know for sure how Toyota implements this feature, but basic electronics says that it should run on HI even if other speeds have gone away. Basically, the FSR consumes some percentage of the available power, for example if there are 4 fan speeds, then the FSR consumes 75%, 50%, or 25%, and when the fan is set to HI, then the FSR allows all of the voltage to pass, or it consumes 0%.
Consume is arguably the wrong word, but the idea is that Ohm's Law states that the available electricity is a circuit is based on the load of the circuit. If the FSR has high resistance, then the available electricity to the fan motor is low because the load of the FSR is high. If the FSR load is medium or low, then the fan speed will increase. If the FSR is no load at all, then the fan speed is maximum.
The resistance of the FSR represents heat, and the heat is destructive. Since there is no heat when the fan speed is set to HI, this speed of the FSR lasts the longest. .