Hi all, i started having issues with the heater fan the last couple of days. When i turn it on, it seems to work fine for a couple of minutes, then starts to slow down (blow less air) and make grinding type noises until it eventually stops. Then if i leave turn it off for a few minutes it will work again but eventually stop some minutes later. I'm pretty sure it has nothing to do with the resistor pack (replaced that once a couple of years ago), since the fan will turn on all 4 speeds (temporarily). Do you guys think that the fan brushes or bearings could be gone or is there likely a connection issue?
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Heater Fan Problems
- Thread starter funkytuqe
- Start date
OK, so i pulled out the blower fan and tested it on the bench for about 20 minutes straight. It worked great, no noise and just pumped out air no problem. So i put it back in the car. I looked at all the connections, no corrosion, everything looks clean. What else can i try?
Reading through the multiple heater/AC threads, it looks like the blower motor can start to draw too much current as it starts to go faulty. Maybe this is the issue, it worked fine when i connected it directly to my battery charger 12V source on the bench, the analog meter was reading about 13A current draw, does anyone know if this i correct or too high? According to electrical theory, if current increases, then the voltage drop across the in line resistance (switch/ connections/ resistor pack) would increase which would inturn result in a lower voltage at the fan power input. This could be why it works when i first turn it on, then with extra current, things heat up and resistance/voltage drop increases. I may even do the switch fix while i am at it just to get that out of the question. Anyhow, anyone know what reasonable current draw for the fan at 12V is?
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I'm having the exact same issue and replaced the blower motor resistor (located behind the glovebox) thinking this might solve the problem, because it did a couple years ago. No dice, didn't help at all. Now looking for a solution also.
I think it might be the fan switch control unit where you control the fan speed, temperature and flow on the console.
This tipped me off as a Tech service bulletin a long time ago.
http://www.mazdas247.com/forum/show...AC-switch-unit-revision&p=4675248#post4675248
Let me know what you find out and maybe can help each other.
I think it might be the fan switch control unit where you control the fan speed, temperature and flow on the console.
This tipped me off as a Tech service bulletin a long time ago.
http://www.mazdas247.com/forum/show...AC-switch-unit-revision&p=4675248#post4675248
Let me know what you find out and maybe can help each other.
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Replace the resistor..
it is in behind the glovebox.
One Plug, Two Screws
it is in behind the glovebox.
One Plug, Two Screws
I don't think it is the resistor, the fan will work on all speed settings when i initially turn it on. after some minutes of operation, the fan stops working altogether. When the resistor pack goes, usually the fan only works on speed 4.
Velothree - thanks for the bulletin, my car is a later 2003 production though so i would assume it has the latest control module (bulletin says the production changed over in 2002). Have you tried any other troubleshooting?
Velothree - thanks for the bulletin, my car is a later 2003 production though so i would assume it has the latest control module (bulletin says the production changed over in 2002). Have you tried any other troubleshooting?
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Not yet other than replacing the resistor, which did nothing. Mine's also a 2003 model, but not sure which motor control module I have. I was just assuming or hoping it would be that.
My fan did the same thing yours did, but now won't even turn on in the beginning. It's frustrating and I don't want to take it to the dealer for a $400+ charge, so was hoping to find some answers on here.
I'll have to check my VIN number and compare tot he bulletin.
My fan did the same thing yours did, but now won't even turn on in the beginning. It's frustrating and I don't want to take it to the dealer for a $400+ charge, so was hoping to find some answers on here.
I'll have to check my VIN number and compare tot he bulletin.
I just checked and I think my vehicle has the latest motor control module also, at least its well above the 150990 serial number.
Now what? I thought maybe the replacement of the control module would solve the issue. Looks like I need to fork over the $$ and take it to a dealer.
Now what? I thought maybe the replacement of the control module would solve the issue. Looks like I need to fork over the $$ and take it to a dealer.
Well, i would take out the bezel and check the connections on the fan speed switch, i am going to try that tonight. I'm going to take off the connections to the switch, clean all connections, and the put it back together (i'll probably try to tighten the connections by squeezing with pliers). If that does nothing, then i will have to replace the fan (about $100 at the parts store). The fan can be accessed by taking out the glove box, there are 3 screws holding the fan to the heater box and it just drops down. Other than that, i guess the module?
Thanks for the link, i didn't disconnect the vent cables, that's probably why i could not get the bezel to come out very far.
Anyhow, the heater fan worked fine all the way to work this morning, i wonder if it's just temporary or if disconnecting/reconnecting removed some oxidization in the connectors or something resulting in better connection. I'll have a go at the controls again tomorrow when i have time.
Anyhow, the heater fan worked fine all the way to work this morning, i wonder if it's just temporary or if disconnecting/reconnecting removed some oxidization in the connectors or something resulting in better connection. I'll have a go at the controls again tomorrow when i have time.
You know, it worked after putting it back together, but yesterday and today i had the same failure. Worked great for the first 10 minutes of my drive to work, then slowly started to die. I think what i need to do is take the connection off the fan when the failure happens and measure the voltage, that should tell me if it's on the control side or the fan it's self. Still not sure why the fan worked great on the bench though, but i guess there would be no inline resistance with a direct connection.
Ok, so the fan died all together, it does not work at all now. Last night i had time to do a little more digging. With the fan controll on high (level 4), i confirmed that i do get 12V to the fan connector input. I highly doubt that it is the controll module or resistor pack since voltage is getting through. I have ordered a new one and it should be here next week. I ended up buying an aftermarket fan from a parts retailer because it was much cheaper than the dealer part ($98 vs $180). Hopefully that was not a mistake, sometimes these aftermarket parts are cheap knockoffs. The part should get to my door next week, i'l post up the results as soon as i install the replacement.
PS, this moring sucked with no heater fan and a frozen/frosted windshield! I'm lucky that the winter weather has been somewhat mild, if it were super cold there is no way could be driving the car.
PS, this moring sucked with no heater fan and a frozen/frosted windshield! I'm lucky that the winter weather has been somewhat mild, if it were super cold there is no way could be driving the car.
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