When I purchased the vehicle used in January of 2015 the fan was working on all settings (heat and AC). It has a weak air flow but not much. Now for the last two weeks the fan speed has been decreasing and then it would abruptly shut off completely on every setting. Three days ago it stopped working all together. I replaced the blower motor resistor and checked the fuse. No luck. What could the problem be?
My car has 160000 miles.
My car has an automatic transmission.
Hi, thanks for writing in. I’d be happy to provide my insight. There are a few other possibilities with this scenario. The blower switch, the blower motor itself, function switch or the blower fan relay could have a problem. What you are experiencing is a high resistance somewhere in the blower circuit. It is the same thing your blower motor resistor does.
You can tap on the blower motor with a small hammer to see if it responds by beginning to work or if it changes speed. This is a very good diagnostic method for electric motors.
There are two possible systems with your car. One has a blower motor relay, and the other does not. If yours has a blower motor relay, this can serve as a good place to do some testing. Testing will require a test light, possibly a multimeter and access to a quality wiring diagram for your car. You will need to understand how electricity works as well.
If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.