Blower Motor Repair Thread - With Photos

[Flat Six]

Engine Compartment Blower Motor Repair

Like others here, my main heater blower motor (in the engine compartment) wasn't working. I determined I was getting +12V at the harness connecting to the motor, so it was time to open it up to diagnose.

After removing the blower motor from the engine bay, separate the motor from the fan housing by unscrewing the three nylock nuts (two shown below, 8mm socket). [PIC 1]:



Holding the outer rim of the squirrel cage fan to not bend the vanes, remove the nut that secures the fan (12mm socket) from the end of the motor shaft. [PIC 2]:



A small circlip on the end of the shaft needs to be removed before the motor end plate can be removed. [PIC 3]:



Two phillips head screws secure the motor end plate [PIC 3] and screw into two square nuts in the motor housing (I used a shop magnet to extract them). [PIC 4]:



Pull off the motor end plate (it'll require quite a tug against the motor magnets); you'll see the brushes on the underside of the motor end plate. My brushes were very worn, and one brush had detached from its lead completely. [PIC 5]:



My brushes measured 0.248" W x 0.310" H; I don't know how long they were originally but I guessed about 1/2". Replacement brushes were a little hard to find; I purchased mine from Eurton Electric | Electric Motor Repair, Rewinds, & Parts for $3.75 each (brush #33M). [PIC 6]:



In my case I was able to (carefully) pull the remaining lead out of the one brush that was still attached, and remove the leads attached to the new brushes. Then I used cyanoacrylate gel to attach the new brushes to the existing motor leads. [PIC 7]:



Used compressed air to blow out all kinds of dust from the armature windings and the motor housing (please wear a dust mask and eye protection!), re-lubed the two motor shaft bearing surfaces, re-assembled, and re-installed. I was fortunate that I didn't have other issues with the motor or any significant play in the shaft, but brushes are a normal replacement item and I'm sure lots of us who have inoperative blower motors can get them back into working order with a brush replacement. Worked for me!

Hope this helps.

Dale

[Joe Bob]

Good job, how much time? Less than ten bucks in parts?

$129 for the motor....

Pelican Parts - Product Information: 911-624-151-02-PH

$462 for the whole assembly.

http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=911-624-151-03-M78&catalog_description=Engine%20Compartment%20Blower% 20Motor%2C%20%20%20911%20%281980-83%29%2C%20%20911%20%281974-79%2C%20requires%20hose%20number%20930-211-031-00-M100%2C%20see%20below%29

[86 911 Targa]

Dale,

Well Done!!!

I repaired our footwell blower motors last year.

Saved $$$.

Gerry

[john walker's workshop]

in the third pic, it looks like the shaft has worn the hole/bushing oblong, which is common. what did you do about that?

[m110]

Originally Posted by john walker's workshop

in the third pic, it looks like the shaft has worn the hole/bushing oblong, which is common. what did you do about that?

Does that mean the whole assembly needs replacing or just the motor?

[Flat Six]

Originally Posted by john walker's workshop

in the third pic, it looks like the shaft has worn the hole/bushing oblong, which is common. what did you do about that?

Sharp eyes, John, but that's just a spacer/washer that looks like a shadow in the pic. Here's a closeup; maybe this helps:



There's a very little bit of axial play in the motor shaft (~1 mm), but I think that's normal. Can't feel any lateral play, though.

Dale

[Flat Six]

Originally Posted by Joe Bob

Good job, how much time? Less than ten bucks in parts?

About 10 minutes to pull the blower (first time; takes less than five now!); another 10 to dis-assemble. Cleaning time would vary, I guess, by application. Figure about an hour tops, taking your time.

Hardest part was searching out a source for the right size brushes.

Dale

[HawgRyder]

How was the commutator?
Did you have to undercut the mica in between the copper sections?
Sometimes one needs to use a lathe to take a thin cut on the comm to get rid of the groove from previous brushes.
Bob

[Flat Six]

Originally Posted by HawgRyder

How was the commutator?
Did you have to undercut the mica in between the copper sections?
Sometimes one needs to use a lathe to take a thin cut on the comm to get rid of the groove from previous brushes.
Bob

Bob, commutator appeared fine and motor ran well when reinstalled. I did pull the motor again subsequently to re-lube the rear shaft support (forgot the first time I R&R'ed ). At that point I did chuck it in my lathe and gave the commutator a very light cleaning with 1500-grit just to make myself feel a little better. But, as I mentioned, didn't seem to need it.

Dale

[1982911SCTarga]

Originally Posted by john walker's workshop

in the third pic, it looks like the shaft has worn the hole/bushing oblong, which is common. what did you do about that?

Has anyone successfully re-bushed the worn-oblong faceplate hole? That seems to me to be the weak point of these motors. I've got two in that condition.

Brian

[Flat Six]

Originally Posted by 1982911SCTarga

Has anyone successfully re-bushed the worn-oblong faceplate hole? That seems to me to be the weak point of these motors. I've got two in that condition.

Brian

I haven't myself, but after having taken this apart a couple of times I can't believe it'd be that hard to machine a bronze bushing to fit & epoxy in.

[roadster49]

I was trying to replace my vacuum lines and in trying to get back there to access them I pulled out the blower. I tried to spin it but it was hard to turn and wobbly. Took it apart, but had a hard time with the nut that holds the fan to the shaft. clambed the shaft with vice grips, but some metal pieces broke off.

Not sure what it did or if it is important. Are these part of the fan or the motor? The armature is shot as are the brushes and bearings so I need a new motor, but want to know if the broken part on the shaft is critical or comes with a new motor. Here is a picture of the fan bottom and the shaft. Thanks for your help in advance.

[roadster49]

Where is best place to get a new motor? Saw some posts for grainger and napa or spring for OEM?

Thanks

[Gogar]

I just threw down the $1xx on PP for the replacement motor; it was one of those things where the ease if replacement was worth it to me.

[JPaul]

I just removed a non working engine cooling fan and took it apart to see what I could spy. Everything looked good so I cleaned up the commutator (brushes are worn but still look good) gave it a little grease on the bearing and reassembled. Voila! Running motor.

Now I have the problem I've seen posted about the footwell motors not working but I suppose that's the subject of another thread.

[Joe Bob]

They might start working.....the circuit requires a running engine blower....

[James Brown]

Would not superglue act like an insulator from the brush and the lead? It seamed to work just wondering.

[JPaul]

Joe Bob,

Just found the control box "reed switch" bypass thread. That's my next Sunday chore.

[Busta Rib]

I attempted this repair this weekend. It is easy to pull the motor and disassemble. My only advice is to be careful when disassembling the lead from the old brush. I got a little too hasty and cracked the board that everything is assembled on. Some super glue to the rescue. Also, there are tiny springs that put tension on the brushes and two square retaining nuts that secure the end plate to the housing. Take care in keeping these safe. I ended up losing one of each and will have to replace them. PITA.

Finally, I need help identifying two parts that fell out of the bell housing as I disassembled the motor. See pic below. Anyone have a clue as to what they are and where they go? They are metallic. One fell out and the other was stuck to the magnets in the bell housing. Thanks in advance for your help.

It turns out that my brushes were fine, but I already ordered new ones from the link provided above so I replaced them. The old ones were half the length of the new ones. One of the coil conduits had been soldered on before and it disconnected so I just need to resolder it to complete the circuit. Once I do this and figure out where the mystery parts go, I will reassemble and install.

Yes, I could easily pay the $125 or so for a new motor, but there is satisfaction in fixing something for $10, even though I will have had about 3 hours into this including time driving around to replace little parts.

[Flat Six]

Originally Posted by Busta Rib

Finally, I need help identifying two parts that fell out of the bell housing as I disassembled the motor. See pic below. Anyone have a clue as to what they are and where they go? They are metallic. One fell out and the other was stuck to the magnets in the bell housing. Thanks in advance for your help.

Sorry; I don't recall any pins like those when I R&R'ed. Reviewed my pics again (including a bunch I didn't post) and don't see anything like those.