Since I got my Outback in Dec 07 I have had the blower motor (Aug 09) and resistor (May 10) replaced. The A/C has quit again and the dealership says it’s the resistor again. Could there be something else going on that causes the resistor to blow out or might I just have received a faulty replacement.
Someone can correct me if I am wrong, but a resistor will blow out if too much current is applied. Resistors are measured in Ohms, each one having a resistance or ohms rating. Sounds to me like there is a short elsewhere causing the resistor to blow. However, I do not know where the problem would be.
I would bet on the fan motor. It may be drawing too much current and the resistor overheats and blows. This usually happens with the slow speed first and then the middle speed and finally the higher speeds. There could be an intermittent short, when a wire with some insulation scrapped off hits a ground.
Update, unfortunately no progress. They thought it was the blower motor surging and blowing out the resistor. That was last Friday, had to wait for the parts to come in today. Lo and behold the A/C is working again so they say it must not be the blower motor. Maybe the master control panel but can’t check that while A/C is working. Trying not to let the frustration come through but, there is obviously something wrong and the dealer can’t seem to fix it.
Have now had the control unit replaced. Picked the car up last night and the A/C is dead again today. They did not replace the blower again this past time, maybe the surge from the short in the control unit damage the blower before the unit was replaced? Taking it back in again tomorrow. Am at my wits end with this. I love this car but the A/C problems are driving me nuts. Escpecially given the heat we’ve had on the East Coast this summer.
Maybe they should connect an ammeter and see just how much current the blower motor is pulling. The odds of a bad resistor are about zero.
If the current draw is abnormally high this could mean a faulty blower motor, an improper fit allowing the squirrel cage to drag on something, etc.
A loose fitting blower motor connector could also cause problems as this increases the resistance in the circuit. This mean arcing and heat.
Are they doing this under warranty or is that up?
Thankfully it’s all being done under warranty.