Those already following the previous thread know exactly where we are on this.
For those that have not been reading or may want to do a more specific search on the repair option might get better use of this title and the directness to the fix instead of just reading about how much we all want to find a fix.

My photos are of the near completed stage, almost ready to go in the car.
I'll disassemble and take better, more detailed pics if they are deemed necessary. I'll also 'hijack' pics that I think are relevant form previous posts and elsewhere if I needed.

Here we go.
Condition:
Footwell blower motor not funtioning; proven to be bad after disassembly and troubleshooting discussed in other posts.

I initially tried to find a brushless motor that would fit INSIDE the existing plastic housing. I couldn't find one.

I then considered the option of modifying the baseplate to accept a larger motor, just as I had done on the rear fan motor a couple of years ago.

That thread is best left to the original discussions that inolve some mods that many may not be comfortable doing themselves, but this is really alot easier than I had initially feared.

I purchased the exact same upgraded DC motor that was used in the rear upgrade. This motor is made by Dayton and sold at Grainger under part # "2M197". The cost was about $25. They have a limited supply nationwide of this particular motor to around 50 units they told me yesterday. They will still be able to order them, but they will no longer be carried at your local branch.

Open the plastic housing by gently prying on the metal clips that hold the baseplate to the fan housing.
Gently pull the cage from the center shaft.
Remove the 2 screws that hold the motor in place.
Press motor shaft against a stop that will force the motor up out of the plastic sleeve.
Throw the old motor away; be sure to keep the fan cage and the metal clips.
We need to modify the baseplate to accept our new fan.
Easy. Cut the housing off w/ a hacksaw or a band saw to leave just over 1/2" of sleeve.
Sand the remaining part away on a belt sander until it equals the space required to clear the 'hump' that surrounds the new motor shaft. I measured this by holding the baseplate against the side of the shaft. If you sand it too much, the existing hole in the baseplate will not be large enough in diameter and you will have to drill it out in order to tighten the baseplate to the motor.
If you sand too little, the shaft may not stick through the baseplate enough to fit securely in the cage. Go slow and try to keep it flat.
Now we carefully drill through the baseplate for new mounting points. It jsut happens that the needed bolt holes are EXACTLY where the circular mold marks are on the remaining part of the sleeve. Use the smallest drill that you have that will let that mounting stud have a little bit of play in the hole in case it's not perfectly parallel.
Countersink the underside of these holes VERY SLIGHTLY. Too much means your bolt hole will now be too large. (The good news is if you screw this up the first time, you can rotate the baseplate and try again with the other pair of posts. This might be the only time you have this much room for beer induced error on your Porsche.)
Now we need to mount it all together.
Tape the two plates on each end of the motor to the motor housing so the internals don't spill out on the floor when we remove the bolts.
Remove the mounting studs/bolts from the motor and insert them from the underside of the baseplate. Now is your chance to check on those countersinks.
Run the studs back through the motor housing and install the nuts and washers on the other end of the motor.
Get a caliper and measure the diameter of the motor shaft. It should be .2500". Drill a hole in the cage that is tight enough to hold and is still a 'press fit' installation. I used a 15/64" drill bit, but it was a bit too snug to make the cage install as easy as I had wanted. I was afraid I was going to break the cage by pressing it on with that much force, but once it started, I was more afraid of trying to get it back off the shaft.
You may decide to try and tap the cage for a set screw to go against the flat on the shaft, but I think it would be dificult to drill and tap the plastic cage without breaking it. Besaides, it was a pretty tight fit anyway.

Use the metal clips to hold the new motor and baseplate to the fane housing and you are done. Put it back in the car and get some heat.

You will have to press the cage on almost until it touches the baseplate, otherwise when the motor and housing are mounted in the car, the shaft will drop enough for he cage to rub on the housing when it is running, making for a terrible noise and a grinding/melting of plastic.

I REALLY dig the fact that this approach uses the same motor as the rear mod already mentioned.

 

Nice DIY, Dan. Thanks for taking the time to post.

Ian

 

Apparently i failed to mention that the polarity for this motor is backwards to our original part. You must hook the black wire from this motor to the + lead on the wiring harness to get the fan to rotate in the right direction. (the red lead then becomes the ground)
+++

 

So reversed it would suck & not blow? Hmmm . . . .

Ian

 

Hey Dan, that is another great fan fix!! I know when my engine compartment fan failed, I was going to use the write up you did to fix mine, but I went a different route. I acquired a 914 fan from a friend, $0.00, I just had to swap out the motors, and the cage type fan, because the 914 fan blades were opposite from the 911 fan and I connected the 911 power plug to the 914 motor. All was great! Once again, great post!! Tony.

 

Dan & folks,
A 2013 update re this mod, which I did last night - and boy is it eerie not to be able to hear the darn things squealing any more - or hear them at all with engine running!

1. Dayton 2M197 is superseded by the essentially identical Dayton 3LCH7, which can be found at all the usual suspects (also a direct cross from another manufacturer). Current price per ranges from <$40 to ~$60. Best deal I found, including tax (CA-CA transaction) with free UPS Ground, was from ZOROTOOLS.com, $82.99 total for two, arrived next day. BTW Grainger don''t carry this as local stock any more - last time I got one (in 2011 to replace the 3.2 engine blower motor, before the 3.6 conversion) they did.

Motor wires: Red to blower ground, Black to blower hot, for correct rotation.

With 90-degree spade females on the motor wires, they can attach to the original on-motor plug & terminal piece, suitably insulated, to form a connector block. That allows use of the original harness connector pigtails without hacking it up. There's plenty of room to stow this "lump".

These motors run at maybe 60% of the original motor speed, but even without the engine blower on my 3.6, they work great, tons of heat.

2. Also on tools & drill sizes I found useful for this job:

2.1 Removing cage: Easy drama-free one-handed slide & squeeze - Harbor Freight Item 67399 panel clip pliers.
2.2 Enlarge cage hole to give 4 thou interference fit with the 1/4-in shaft - D letter drill (0.246in).
2.3 Set 6-in vernier calipers to 0.560in and you can scribe a cut/belt-sand-to line around the original motor pocket, using the flat face to slide the caliper around as one reference.
2.4 Motor mount holes - 19 number drill (0.166in).
2.5 Motor mount holes relief - instead of using a countersink, 1/4in & 3/8in forstner bits made nice flat-bottomed recesses to hide the coach-bolt style head & square.
2.6 Locktite on the two nuts seemed prudent.

Again thanks Dan! I kept your post a few years now and it paid off really well!

 

Barry,
Thanks for the tips and info!

 

Verily you be most welcome, Scott! BTW it took 3 hours for 1st (much of it wearing the usual p-car-mod-pondering blank expression), and then a mere 1/2hr to do the second, followed by a successful late, cold night heater test drive and a very satisfying martini on return

 

My passenger side squirrel cage was friction welded onto the housing. Took multiple blows with a chisel and hammer to remove it. Once off it ran well. No idea if it had been that way for a week or for twenty years. Decided to just bypass it with some ducting. Drivers side I didn't even bother to check to see if it was working before deleting it too.

 

Lucky dog, Amber Lamps! Obviously it depends on your particular setup & weight reduction program . I certainly would've done what you did in the 14 years I ran the 3.2 if I hadn't had a half-dozen spare FW blower motors (great deal from Autobahn in San Diego), and before I transcended KISS (Keep-It-Stock Syndrome) - the darn things were always going out - on a road trip, one caught fire in torrential winter rain on a rush-hour freeway in Seattle, and filled cabin with acrid smoke

With a working engine blower, presumably there are no problems getting hot air without FW blowers, which IIRC weren't even fitted to earlier cars.

Also IIRC, on some 3.2 Carrera, FW blowers run at low speed either all the time, or at least (like my '85's 3.2) when the engine blower turns on when the engine gets hot, via engine compartment blower control module, to add a bit of extra engine cooling - this was (rumored to be) that on earlier FW blower-equipped cars, with FW always blowers off when the heater was, overheating in the slow-moving but very hot air present caused seizing via the brush assembly, or the cage deformed onto lower part of housing, perhaps latter is what occurred with yours.

For those of us that still desire heat but have removed the engine blower and added a bypass tube (as with my 3.6 conversion), we have to have working FW blowers, of course.

2U2