A/C, Heater Motor Issues--Advice Appreciated...

[JT95]

I have a weird issue going on with my climate blower motor. For no apparent reason, the blower will sometimes just stop working. Turning the switch off and then on does nothing for it. Sometimes it just starts back up again on its own, sometimes not until after the car has been shut off and sat until next drive. I can hear a little electrical blink or click coming from inside the dash on the driver's side when the switch is turned from off to on, even though the blower motor does nothing. The a/c compressor will still kick on too when the blower motor has stopped running.

 

What could be going on here? If the squirrel cage had a bad motor, wouldn't it just go dead for good? What do I need to check out? I'm not the best at electrical troubleshooting, and I hate to rip the dash apart on a ghost chase.

 

Has anyone one else had this issue? My car is a 99 Impreza.

 

 

Thanks for any helpful input!

[OB99W]

When the problem shows up, does the blower run if you set it to the highest speed?

[JT95]

When the problem shows up, does the blower run if you set it to the highest speed?

 

Nope--the blower is completely dead.

 

 

Now, I did have an issue a few times last year where the blower would go from full blast to like a 2 power on its own when the A/C was turned on. I turned the A/C off and it would go back to normal power after a bit. It did this a few times and then never again, but the blower never randomly quit working altogether until this past week.

[OB99W]

Nope--the blower is completely dead.[...]

If the blower doesn't even work on the highest speed setting, then that eliminates the blower resistor as a possible problem area. I could explain how to troubleshoot this with a voltmeter, but it sounds like you're not feeling up to that. There might be a bad connection at the relay, or the relay contacts could be burned. Try rapping on the dash where you hear the "click" coming from and see if the blower comes back on (even for a moment).

[Rooster2]

I had same problem with my Legacy. I thought the fan motor was bad, but upon replacing the unit, it turned out that the blower unit was full of tree leaves and crud. Cleaning out the mess fixed the problem.

 

It is easy to access the fan motor. Simply remove the glove box, and the unit sits there right in front of the firewall. Use simple hand tools to remove, and clean out.

 

I am fairly confident this is your problem, particularly if you leave your car outside, and park under trees.

[JT95]

There might be a bad connection at the relay, or the relay contacts could be burned. Try rapping on the dash where you hear the "click" coming from and see if the blower comes back on (even for a moment).

 

Do you know specifically what the relay looks like? I plan to crawl under the dash this afternoon and try to decide exactly where the little "blunk" sound comes from when I turn the blower switch on and start from that spot. I have a volt meter, so I suppose I could at least see where the line of power might go dead and then check back for advice on what to do from there.

 

I have a parts car that can hopefully provide any parts I might need if something heeds replaced.

 

 

And, I will also check and make sure there isn't a mess of debris in the squirrel cage. My car stays outside, but not near trees. But, I've only owned it a couple years, so who knows where it used to park. I would think a clogged blower would still make some sort of noise, like it was struggling, but who knows. I just gotta figure something out because it def is not safe or comfortable to have no blower motor.

[OB99W]

Measuring with respect to a good ground, with the blower control speed set to the highest position, you should have battery voltage on the black/red motor wire (hot lead), and very close to zero volts on the black/yellow motor wire (ground lead).

 

If those voltages are correct, then either the blower motor is stuck or defective.

 

If the voltage on the black/red is too low, trace it back to the relay, and check the voltage at the red/white wire -- if it's okay there, then the relay isn't closing or making good contact.

 

If the voltage on the motor's black/yellow wire is much above zero volts, then the fan switch ground isn't good (black wire at the switch) or the switch itself isn't making good contact.

 

If you can't make sense of meter readings you get, let us know what they are and under what conditions you got them.

[JT95]

Thanks, OB99W.

I may not be able to dive into this until the weekend, but you def gave me some help.

[tcspeer]

I think if you will look up under the dash on the left side and find the plug that goes to the blower and give it a good wiggle and push back on the connector you may solve your problem. I have had this issue a few times already and that was my problem.

Edited April 26, 2010 by tcspeer

[JT95]

Turns out the blower motor was indeed dead. Luckily, I had a spare from a parted out OBS, so it was a fairly quick and easy solution.

 

Of course, the motor itself was the very last thing I checked, naturally...

 

 

That was my weekend accomplishment in the middle of our flooding rains. Now I'm hoping that my airbag light is as easily fixed when I swap out the clock spring from the same donor car in a few weeks.