Heater fan problems ...anyone with some help please?

[pingber]

To begin with. lets just say that my dealer wants to replace the entire fan motor/housing etc ..I'm not convinved because here are the symptoms.1) fan works great, quiet on ALL speeds2) When the fan is working, switch is working too.3) Here's the problem ...after running for a while, usually in wet weather, summer or winter, after shutting car off, heater blower will not restart.4) At that point, the switch is still working OK, becuaser when set to any of the defrost settings, I can hear the A/C compressor kick on.5) Now don;t laugh too hard ...If I slap the area of the lower glovebox where it is hinged to the dash, and give it a good rap, the fan turns back on and it will work again for a week or two.Any ideas on where to even start looking? It seems like something is loose, although I can;t figure out the dampness relationship at all.TIA

[pmw061299]

I'm having the same problem. Does anyone have a suggestion. I've been told it could be an electrical short, or a bad blower.I just found another thread on the site. Try this; it might help.http://forums.genvibe.com/zerothread?id=35535

[kevera]

I'd say blower.

[ipick]

I had/have the same problem. When fan works it works fine at any speed, when it doesn't i can hear the AC comp kick on but the fan does not.My fix: just to the right of the fan control unit on the side of the console, give it a good swift firm hit with the palm of your right rand, Instant fix. It's done it to me about 5 times in the past 5 months now.

[ned23]

It sounds like one or more of the brushes in the motor is stuck or worn. The brushes are held against the motor armature by springs. So, when you "bang" the motor, what you're doing is jiggling the brushes loose so they flush up with the motor and make contact. Now, in some motors you can replace the brushes and/or clean and lube the springs with graphite or whatever. There are usually screws on either the side of the motor that you remove and the brushes and springs are inside. Now, I have absolutely no idea if the brushes on these particular motors are accesible like that. Maybe someone else does. If not, try getting another motor from a scrap yard or something.

[ned23]

Here are some photos. (Now, i suppose it's possible that they're using brushless DC motors for car HVAC now but that used to be kind of pricey technology and a little high-end for a heater motor).These are DC motor brushes:Look toward the rear of this motor and near where the cord goes in you see a raised screw about 1/2 inch in diameter. That's usually where the brushes are:

[ipick]

When I say "fan control Unit" i mean the fan speed switch/temp selector unit in the console. Smack the console to the right of if by the chrome trim.

[ned23]

Quote, originally posted by ipick »When I say "fan control Unit" i mean the fan speed switch/temp selector unit in the console. Smack the console to the right of if by the chrome trim.Ah, okay. That's a little bit different then smacking near the motor. I have no idea what it is. I had a similar problem on a 1996 Tracker but I can't believe that it is in any way related. In that case, the switch that controlled the fan was housed inside of a two-piece case that snapped together. The contacts were on the "lid" of the case and the switch lever was in the bottom half. The "lid" got loose on one end and didn't make contact. I solved that problem by taking the dash apart and using a heavy "zip-tie" to sandwich the case back together. Eventually that loosened up a little so I went in again and whittled a "shim" that I pounded between the case and the tie to tighten the lid down again. Horrible design!

[wyatt89]

Mine just makes an annoying knocking noise when it's on low or medium low...it's really annoying...

[TheGreyOne]

I FOUND A FIX !!!!My fan was automatically changing it's speed. When I'd turn it onto high it would rev out for moment, then slow down. Sometimes it would speed up again when going over a bump. I read this thread and thought maybe I'd change the resistor pack and/or the motor.THEN the fan quit... totally, when I left for work at -27C temperature. About two blocks away, it started all of a sudden. On the commute home (25km) it quit again. The windows were fogging up, so while stopped at a light, I thumped the right side of the dash near the chromed part and it worked.Next day is was a little warmer at -21C, but it TOTALLY quit. Once at work I thumped upwards underneath the glove box (later I realized this was the PCM... oops!). It worked.Now... the temperature went up to a wonderful -12C so I got under there with a flashlight to check for loose wires and also to see if I could find any access to brushes. I took out the single screw on the right hinge of the glove box and removed it.I saw that the brushes were just held in with a small rectangular rubber grommet affair. When I put slight pressure on it... the fan quit! Damn! But then when I pushed in on the rubber I must have been freeing up a stuck brush and the fan started, stopped then started again. I did the same to the other side. I DIDN'T remove the rubber or the brushes because they are likely spring loaded... so only pushed in and out on the rubber end itself.Two days now and I have all speeds and no automatic changing of speeds nor times when the fan quits. Looks like I fixed the problem !!!!

[chris777]

whatever it is this looks like the problem i have. My air completely quit a few weeks ago for no reason, Just cranked it u and it didn't start blowing at any speed. the ac compressor works because you can hear the compressor drag on the engine idle speed. Then it worked again for a couple of weeks no problem. Then it went out while driving, and i could make a sharp turn or go up a hill and it kck back on. I am about to pull the glove box and tke a look but I am hoping it will be the issue Thegreyone found and will be a cheap IE free fix.

[TheGreyOne]

Yes Chris777, it's been over a year now and just 3 weeks ago it occasionally the fan would not start up when I started the car to go to work. I just grabbed my snow brush from the back seat and thumped under the dash under the glove box and it started again right away. It's happened 4 times recently and always just when I'm going to work so I never remember to look at it on the weekends... and letting the weather warm up a little more incase I screw things up and actually have to buy some new brushes this time !!!!The single screw is not a problem to remove. And I will again just try pushing in and out on the little rubber pieces to free up the spring loaded brushes behind. I MIGHT take a chance this time and try to carefully remove the rubber piece, spring and carbon brush to see how much is left. I might try stretching the spring a little to have it apply a little more pressure on the brushes. Or replace them IF I can get some. Does anyone know if one can buy just the brushes... or do we have to buy a complete heater motor ????? Some electrical motor place should have brushes, eh ???

[chris777]

I have been using the give it a whack method since finding the problem. However, it is becoming a near everyday issue.

It has been a bit since I disassembled the blower. But I don't remember seeing anything like the brushes. I know its a drum fan, is there somewhere in particular I need to look for the brushes/springs/gaskets at in relation to the motor?

otherwise I may have to get a new motor soon myself.