So, my car's fan stopped working. A little help?

[mareakin]

Which fan: The fan that blows air into the interior of the car to keep me comfortable, NOT the one mounted in front of the radiator to cool the engine. (side question: what is this fan called? is it the AC fan? The blower motor fan??)

The story: So, one day, it just stopped working. There are no causative events, it just stopped working. I turn the control from off to slow all the way to highest, and... nothing.

I'm thinking of checking the FUSE first.

Here's a cut and paste of the manual

Which fuse do you think controls this fan?

--------------------------------------------------------------

If it's not the fuse, I think it's probably the motor itself located under the glove box.


PS: Car is 2007 Toyota Corolla. It stopped working on a very cold day, my hands were freezing.

Thanks.

 

[AandPDan]

I'd guess 40, HTR.

I assume it means heater. There's no way anything except the fan should draw that much.

 

[SteveSRT8]

There's a huge resistor made of coils of wire that is usually in the evaporator enclosure.

That's usually the problem. Check the motor by jumping power directly to it.

Then fuse and switches. That's it unless there's a wiring issue.

 

[fsdork]

+1 for the resistor. I had one fail on my Civic, replacing it fixed the problem.

 

[mareakin]

Blower motor resistor? Ok, I'll look into that for its location and replacement procedure. Thanks for the tip.

UPDATE: But wait, does not the resistor control the fan speed only? In my case, the fan doesn't come on at ALL!

 

[SteveSRT8]

A blown resistor can cause the motor to not come on at all.

 

[mareakin]

Originally Posted By: SteveSRT8
A blown resistor can cause the motor to not come on at all.


Got it. I'll add that to the list of things to check. Thanks.

 

[mareakin]

UPDATE: Got into the car today and everything worked. The fan came on and is working normal. How strange... it wasn't working for two days and magically it worked today. This is puzzling.

Some theories:

1. ECU/ECM causing this. My car, 2007 Corolla, has a ECU recall that has not been performed. The recall is for a failing ECU that may stall the car. It's a safety recall. I haven't done the recall because I figured I didn't really need to and am a bit worried that new ECU might degrade it's performance.

2. The last two days, when I started the car in the early morning (3am) in freezing cold temperatures of 30 degrees. The fan wouldn't come on at any setting. Today, the temperature is around 45 degrees and it worked normally. Might this have something to do with it? Possibly, let me explain. The fan has slowly degraded over the years of ownership and for the last two years it's been making a slightly audible chattering sound. It's something I can tolerate but I knew the fan would die someday, in the near future. My guess is that the cold temperatures built some frost in the motor fan which obstructed its movement and the warm temperature melted it away, so now it's working.

Any comments?

 

[Tegger]

Originally Posted By: mareakin
Some theories:

1. ECU/ECM causing this. My car, 2007 Corolla, has a ECU recall that has not been performed. The recall is for a failing ECU that may stall the car. It's a safety recall. I haven't done the recall because I figured I didn't really need to and am a bit worried that new ECU might degrade it's performance.

The vent fan problem has zero to do with the ECU.

The new ECU will not "degrade performance", the recall is prompted by cracked solder on certain circuit boards. A manufacturing defect, in other words. Considering the fix is free to you, you're a bit foolish to avoid having it done.

Originally Posted By: mareakin
2. The last two days, when I started the car in the early morning (3am) in freezing cold temperatures of 30 degrees. The fan wouldn't come on at any setting. Today, the temperature is around 45 degrees and it worked normally. Might this have something to do with it? Possibly, let me explain. The fan has slowly degraded over the years of ownership and for the last two years it's been making a slightly audible chattering sound. It's something I can tolerate but I knew the fan would die someday, in the near future. My guess is that the cold temperatures built some frost in the motor fan which obstructed its movement and the warm temperature melted it away, so now it's working.

Do the easy thing first: test the fan motor. Unplug the electrical connector from the motor, and jump battery power and ground directly to the motor. If the motor is defective, you'll know right away on account of the noise or slow starting. Power goes to the pin that runs tangentially to the motor housing.

 

[Scott_Tucker]

When checking fuses I recommend checking all of them. You can never trust the labels to be 100% accurate. Also, you may find another fuse that has blown that you weren't aware of. I've been bitten a lot by only checking the fuse I thought was the one I needed to check.