Air conditioner/heater fan not coming on

Hello, I have a 2006 Toyota Corolla with 106,000 miles on it. Sometimes when I turn on the air conditioner/heater fan, nothing happens. It doesn’t blow any air at all, hot or cold out of the vents, and it makes no sound. Other times, when I turn it on, it works fine and it blows ice cold air out of the air conditioning vents like it’s supposed to. I always try to remember to turn off the air conditioning when I leave my car before I turn off the engine, but it seems to make no difference as to whether the fan will work the next morning when I get in my car. Can anyone tell me what’s wrong with the air conditioning/heater fan, and how much it will cost a mechanic to fix it? Thanks!

The next time the blower doesn’t come on, set the blower speed to high, then reach under the passenger side of the dash and with the handle of a screwdriver rap on the blower motor.

If this causes the blower motor to operate replace the blower motor.

Tester

Thanks, Tester, for the suggestion. I’ll try that. I’ve never looked under the passenger side of the dash, so I’m not sure what the blower motor looks like. Is the blower motor replacement an expensive job? I do have a trusted local mechanic who has worked on my car for years, besides the dealership.

Here’s what the blower motor looks like.

https://www.rockauto.com/en/moreinfo.php?pk=1375653&cc=1432846&jsn=354

Tester

Thanks Tester. I also Googled blower motors and it looks like at my local O’reilly’s auto parts they go for around $70. I heard that sometimes it’s the resister that’s the problem and sometimes the entire blower motor?

When I leave my house later today I’m going to try the screwdriver tapping if the fan doesn’t come on.

It’s not the resistor.

If it were, some of the slower speeds wouldn’t work. But the high speed would still work because the voltage for the blower motor by-passes the resistor.

Tester

OK, thanks Tester

It’s probably the fan motor is on the verge of failing as Tester suggests above. If that doesn’t prove to be the problem, other possibilities are the cage is getting stuck by debris that has gotten sucked in, not an uncommon problem, or the switch that you use to turn it on and off is failing. Tester is spot on about the resistor, unlikely.

One thing you might could test yourself, when you turn the AC on the engine compartment fan should start to spin. Does it? If it doesn’t, that could point to a problem with the AC system, not the blower fan motor.

Your mechanic hopefully won’t just replace the fan motor without doing some further testing. First test, they should make sure the motor connector is good and the motor is getting power. If it’s getting power and not turning, that’s the time to replace it.

The blower motor is a likely suspect for the kind of problem you are having. If tapping on the motor doesn’t get it working again after it has failed you could try running power directly to the motor to see if that helps. If it does then I would suspect the blower relay is causing the problem. Faulty relay contacts can cause intermittent problems like this also.