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Guest Message by DevFuse
 

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Heater Blower Motor intermittent failure solved - '93 Legacy

Heater Blower fan Heater fan heater motor heater fan heater blower

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9 replies to this topic

#1 BB's93LegacyL

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Posted 18 August 2014 - 03:37 PM

Solved for now at least.

I read on this forum that one cause for a heater motor not working properly is debris gets into the squirrel cage. When I took the motor off and cleaned a few pine needles out of that area, the problem still existed when I put the motor back in.

I found that if I lightly tapped the motor body it would start up, but it was making an intermittent ticking noise. After a few days of this, it started coming on more slowly when I tapped it, gradually coming up to speed. I decided to buy a new motor, but I had some questions about the right part, so I took the motor out of the car again to check some features of the OEM fan motor for comparison to the aftermarket parts.

This time I also removed the motor body's silver bottom plate held on by two gold-colored screws (circled on photo). With the plate removed, about 2 tablespoons of copper dust, decomposed vegetation fluff, and spruce needles came out (21 years worth!) FYI, copper dust is toxic, so use proper personal protection.

Since the motor brushes are at the bottom of the motor, the armature at the brushes was trying to churn through all this crud.

 

When I put it back together it seemed to work normally again, but time will tell. Earlier posts have asked about how to remove the motor. Here are the steps... (If you just want to check for dirt in the motor itself, just do steps 1, 8, and 9.)

1. Remove glove box door by removing two phillips screws under the bottom edge of the door.

2. Remove the door's mounting plate by removing 4 phillips screws

3. Pull the plastic corrugated tube off the motor body

4. Loosen the hex head screws behind the two access doors shown in the photos. Loosening these a bit allows just enough flexing of the dash to work the fan from its housing.

5. Remove the 3  8mm hex screws holding the gold-colored base to the black motor housing

6. Lower the fan while pulling the loosened dash panel to the passenger side just enough to get the fan motor and squirrel cage out of the dash

7. Disconnect the wires' connector plug at the base of the motor or at the other end

    Clean debris from the fan housing, and then

8. Remove the two gold covered screws from the silver base blate on the motor, and find where two soft plastic flaps (look like electrical tape) cover the spots where you can insert a flat screwdriver to pry the base plate off.

9. Tap the motor body, and the debris will fall out of the bottom of the motor. The photo shows how much came out on half of a paper towel!

Attached File  P6183076Web720W.jpg   46.7K   48 downloads

Attached File  P8173254Web720WHi.jpg   107.54K   50 downloadsAttached File  P8173266Web720WHi.jpg   41.16K   47 downloadsAttached File  P8173276Web720WHi.jpg   46.21K   41 downloadsAttached File  P8173277WebHi720W.jpg   46.08K   36 downloads


Edited by BB's93LegacyL, 18 August 2014 - 10:29 PM.


#2 Olnick

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Posted 18 August 2014 - 04:47 PM

Nice write-up and very good pix.  This should be really helpful to others down the road.  Thanks!



#3 forester2002s

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Posted 18 August 2014 - 06:32 PM

Yes, great write-up. Thanks for doing it.



#4 BB's93LegacyL

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Posted 18 August 2014 - 08:02 PM

Thanks Olnick & Forester, I've gotten so much help from the people on this forum, I'm just trying to pay it forward. If you have any suggestions for putting the right keywords on a thread so it is most useful and findable I'd appreciate hearing from you, or anyone with experience on USMB.

I should mention, this job is very easy to do for anyone as long as they are able to contort themselves to work under the dash. I have just basic knowledge of working on cars.

Anyone attempting this project could get by with two tools -- a #2 phillips screwdriver, and a flat screwdriver for prying the bottom plate off the motor body, and for popping off the covers on the plastic dash for access to the screws that need to be loosened to flex the dash out of the way. Truth be told, a butter knife would probably substitute for the flat screwdriver for this project. It's nice to have the metric sockets for Philips/hex head screws just because of the better grip on the fastener (I hate Phillips-head screws, but that's just because I have lots of experience with fasteners in corrosive environments, and anything with a Phillips head is worthless there, unless it's stainless, but a hex-head is still better.) That being said, even though this is a 21 year-old car, I think the Phillips screwdriver could do the job without stripping out the screw-heads, because this is interior work where there is no corrosion.

Be careful when shopping online for a replacement fan motor. Sometimes you will see an AC condenser fan showing up cheaper, but that is not the part you want. I saw that the aftermarket motors have wires coming from the motor instead of a quick-connect female plug on the motor body, so replacing the motor is not as simple as just plug-and-play. This might be a situation where it would be worth checking the salvage yards to get an OEM motor from a vehicle with low mileage, do the cleaning I did, and install the OEM motor.


Edited by BB's93LegacyL, 18 August 2014 - 08:31 PM.


#5 Rooster2

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Posted 18 August 2014 - 08:52 PM

years back I had same problem with 91 Leggie. I went to install a replacement blower motor with one from a yard. Upon swap out, I found leaves and crap around the blower. I cleaned up the mess to find out that fixed the problem. I prolly still have the replacement blower unit from a yard stached away in my garage somewhare, that I never used.. Seems like a common problem that develops if you park under trees



#6 BB's93LegacyL

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Posted 18 August 2014 - 10:21 PM

Rooster You nailed it - don't park under trees, especially during the seasons when they are in flower, or when dropping needles and leaves, and during high winds. Otherwise, just think about cleaning out your squirrel cage and motor innards as a routine part of maintenance, maybe every 5 years. I know this car was not parked under trees for the first 13 years of its life -- it was my late father's car that he purchased new. I was the one who parked it under trees (spruce and sumac) in my driveway occasionally when it was not garaged, and at certain times of the year it rains tree debris. Good comment! I was impressed to see how well this 21 year-old Subaru responded to having this cleaning done.



#7 Rooster2

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Posted 18 August 2014 - 11:03 PM

Rooster You nailed it - don't park under trees, especially during the seasons when they are in flower, or when dropping needles and leaves, and during high winds. Otherwise, just think about cleaning out your squirrel cage and motor innards as a routine part of maintenance, maybe every 5 years. I know this car was not parked under trees for the first 13 years of its life -- it was my late father's car that he purchased new. I was the one who parked it under trees (spruce and sumac) in my driveway occasionally when it was not garaged, and at certain times of the year it rains tree debris. Good comment! I was impressed to see how well this 21 year-old Subaru responded to having this cleaning done.

Yea, Subies are designed and built well, and mostly easy to work on .With care they last a long time.



#8 JasonDairs

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Posted 19 August 2014 - 12:38 PM

I was thinking of checking this on my 94 Legacy. My AC cuts in and out randomly. The air keeps blowing, but is no longer cold. Then I hear a click, the RPMs lower a bit, and the cold comes back (usually for 5 mintues). Do you thinking cleaning out this will help? I thought a relay may be at fault. I guess it can't hurt to see if it's dirty in there.



#9 Pgh_Scoob

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Posted 19 August 2014 - 01:09 PM

JasonDairs you are low on Refrigerant... That click you hear with the idle drop is you A/C compressor cycling on.... While your A/C system is low at points it will cut off the compressor because there simply isnt enough pressure to have the system working properly... I would get a EVAC/Vacuum test, Dye Test after the shop verifies no leaks in the system with the Vacuum test and Recharge to the proper amount... Dont believe what you see on TV about this refrigerant blows colder than the rest and you can be "you own A/C pro".. If your system is working properly it will blow as cold as its going to blow no matter what.

Sometimes you can get away with just adding your own can but I have see many cars come in that tried that and ended up blowing out system.

 

Sorry for the off comment... But this is definitely going to be remembered and probably checked out for my 96 legacy... it blows rather well but I have noticed at points it seems like the flow is rather weak... Wont hurt to clean it out.

Thanks

Greg



#10 BB's93LegacyL

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Posted 19 August 2014 - 07:01 PM

Pgh_Scoob, I should mention again that before I cleaned the debris out of the fan motor body, it had a series of symptoms in the following order. The count of days is approximate, just to give some kind of timeline showing how hard the fan motor had to work against the organic matter build-up.  

1) Day 1-10 I heard a ticking sound coming from the area of the fan motor, but everything still worked normally

2) Day 11-20 the motor started to fail to turn on, first for maybe ten seconds, then longer and longer. Sometimes hitting a bump in the road would cause the fan to start. This is when I first removed the fan and cleaned out the squirrel cage.

3) Day 21-27 the motor never came on unless I tapped on the motor housing with my fingers

4) Day 28-34 when I tapped on the motor housing, the fan would start, but not turn at full speed. The speed would gradually rise to normal.

Then I took the motor out, and removed the base plate in order to remove the organic debris.

In hindsight, all of these symptoms (especially ticking sounds coming from the motor) told me the problem was the motor rather than the resistor pack or relay.

 

btw, no problem with the off-topic comment, it is remarkable that my 21 year-old Subaru still puts out lots of cold air with the original refrigerant. These are really good cars!


Edited by BB's93LegacyL, 19 August 2014 - 07:23 PM.






Also tagged with one or more of these keywords: Heater Blower fan, Heater, fan, heater motor, heater fan, heater blower

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