Intermittent Blower Motor Failure - Toyota Nation Forum : Toyota Car and Truck Forums

dimwittedmoose51 · 01-31-2011, 09:03 AM

Been dealing with a fairly noisy blower motor over the last couple of years in our 99 Corolla VE and although it only did it once or twice last summer during AC season, it's doing it more frequently this winter. Doesn't seem to be a fuse, since it comes back to life in a day or two usually and the green dot light in the AC button comes on sometimes when it's turned on. IS that supposed to happen because I don't remember that being the case in previous winters?

Are we talking a bad fuseable link here, a bad relay(if so where the heck did they stick THAT relay?), or WCS, tearing out the dash and replacing the motor. I'm prepared for the dash teardown as soon as I get the Legacy's clutch replaced and out of the warm garage

TIA

DM&FS

Bennie · 02-04-2011, 04:13 PM

Since nobody seems to have any suggestions I'll make a few...

1st off, if the blower itself is loud it could be bad or at least in need of oil. I'd pull it out and bench test it. You would be able to tell pretty easily if it seem like there is a shot bushing/bearing or what's up with it. Maybe you can get away with just oiling it.

2nd, I'd be surprised if the intermittent part had to do with the blower motor. They are pretty hard to kill as long as you put a drop or 2 of oil on them when they start making noise. I'd check the blower motor resistor. It's mounted right next to the blower motor. It has 2 screws holding it in and has a harness with 4 wires. I've had to replace them on both my Prizms. If any of the traces look burnt that's a sure sign it's bad. Sometimes they look ok though even when they are shot. Usually when they go you will loss the lower fan speed but it will still work on high. They cost about $25 from Rochauto.

Hope that helps....

dimwittedmoose51 · 02-04-2011, 05:38 PM

Thanks Bennie: My problem is that now the blower motor doesn't work at all now so it has regressed from the working every once in a while. Will get to the diagnostic phase tomorrow, but I have one question; should the green AC light come on when the heater fan is turned on and the AC button is in the outward OFF position? Could that be some sort of clue as to what's going wrong here? The reason I ask is that the fan reisitor symptoms are not what I'm experiencing ie the high speed only operation, I could live with that right now.

Any ideas are welcome, especially the one that solves the problem!! I will pull it and oil the sucker for sure.

DM&FS

Bennie · 02-04-2011, 09:54 PM

It will come on when you have the defrost selected and fan on.

Good luck with the trouble shooting.

dimwittedmoose51 · 02-05-2011, 03:49 AM

Good to know, Bennie Thanks. I think I can eliminate the switch as a possible problem now. Relay, resistor, or fan, maybe I get lucky and it's a loose wire.

DM&FS

There's a new all you can eat restaurant in town. It's called Bulimia's........the line for the bathroom is really long- Steven Wright

dimwittedmoose51 · 02-06-2011, 10:24 AM

Got the motor out and bench tested it and it's not only quiet when chucked in a vise, it works perfectly. I am curious as to how you access the "oiling" point and when I opened up the black plastic inspection port, I saw no easy access to any bearings. If removing the squirrel cage fan blade is necessary, I'll need some tips on removing it from the shaft/spindle, as it's on there pretty tight and I'd like to not break it if possible. There is maybe 3/16"-1/4" play in the shaft(in and out play), and since the bench test was done with the squirrel cage horizontal and not facing up, that might be a noise issue, but I'll check that when I get back outside.

I did pull the resistor out and the forum won't let me currently post attachments, so I can't send a photo of it, but the white ceramic part has a couple of cracks in it. Upon "massaging" the crack, it spread almost all the way across the narrow side of the ceramic block and in between the copper lugs The solder lugs coming out of it have some greenish gunk on them, but the 4 male spade terminals on the unit have no burn marks and neither do their female counterparts on the plug.

I guess I need to know if the cracking is the reason for the total failure of the system as opposed to the "High speed only" operation that most folks get. Maybe time for a continuity check, but I'm pretty sure I've found the problem. The relay up by the pass. side headlight looked good as did the 50A fuse up there. The gradual cracking might explain the intermittent nature of the failure over the past year too, maybe.

TIA

DM&FS

Bennie · 02-06-2011, 06:00 PM

I wouldn't even remove the fan wheel if everything is sounding good. I'd just put a drop of oil on the back side around the shaft and spin the wheel a little to work it in. It sounds to me like there is no problem with the motor.

It does sound like you most likely have a bad resistor. They are cheap so I would replace it.

As far as the noise goes, look around in the fan housing and make sure there is no debris in there (most common thing is leaves).

dimwittedmoose51 · 02-09-2011, 09:57 PM

Blower Update: After tthe bench testing, I re-installed the motor in the car and put the cracked resistor unit back in and wired everything up. Turned on the ignition switch and clicked the fan on and it worked........once. Shut off ignition and tried it again and the blower motor wouldn't run. This is crazy. NO fuse blown that I can see, so now what?

I tested the two black wires out of the connector to the blower motor and they show 12vdc. When I turn on the fan switch, I hear a click coming from the pass. side headlight area, so I'm pretty sure the fan relay is working. When I hook up 12 vdc directly from a good battery to the blower motor, it won't turn. Can't believe the motor blew between the walk from the shop back to the installation in the car; the CEL came on this morning, but I doubt that that has anything to do with the blower motor.

Guess I'll pull the motor once more and try the bench testing again.

I'm avoiding just buying parts to throw at this repair, but simple diagnosis doesn't seem to be working either.

Bennie · 02-10-2011, 07:34 AM

That sucks it's not straight forward..

If it were me I would replace the resistor either way. If you say it's cracked than it needs to go. They are the cheapest part in the system. From my experience those are the number one failure anyways.

The motors are pretty reliable but if your's isn't running when you put 12V straight to it than obviously it's bad too.

Honestly I would start with just the resistor. I hope I'm not pointing you in the wrong direction with that advice but you can see my reasoning above.

dimwittedmoose51 · 02-14-2011, 09:18 AM

Out of sheer curiosity, I pulled the blower motor out and re-bench tested it and it spun just fine with direct 12vdc, so I put it back in and redid the HAynes diagnosis steps. Funny thing, but turning on the fan switch got the blower motore to work again.....once. Turning ignition key off and re-energizing the system and now the blower motor doesn't work. Bennie is likely right that it has to be the resistor despite no hi speed operation. I went to Advanced and ordered one Saturday night and it should be here this morning. My money's on this being the fix now that I've gone through this whole mess. The parts guy had never seen none cracked like that and the car had been in a minor collision with the PO, but I would think it would take a pretty good whack to crack an enclosed ceramic block like that.

We'll know the answer here in a few hours....

Thanks

DM&FS

dimwittedmoose51 · 02-17-2011, 08:42 PM

Four days now and the fan motor resistor has seemingly solved the problem. The blower motor may be close to failing as it runs real slow on the slow speed. Might have something to do with the fact that I may have put in too heavy weight an oil for the lube in the blower motor. Will use Triflow next time instead of motor oil.

One comment on Advanced Auto's Intermotor line of Chinese made parts....They Suck!! The 4 pin plug from the Corolla would not fit in the female part of the blower motor resistor. Could not for the life of me figure out why they would not mesh. Finally ground down the female receptacle(yeah, there goes the "warranty") to where I could more easily access the male spade ends and they appeared to be out of index somewhat. Can you spell cheap cheap cheap??I was able to wedge them on finally and hopefully we'll not have any further issues. Will put the glove box back in tonight and then figure out why the MPG's are slipping. I'm betting on the 11 year old O2 sensors, but I'll test them first. Amazon has both front and rear Denso's for under $100 for the pair!!

Thanks

DM&FS