sstrickstein

When my blower motor died last summer, I bought a used replacement and put the old one on the shelf. Recently the used one is making noise. So I hatched a plan to rebuild the old unit. I checked around and no one had an answer. I did get one option of using a different unit and rewiring it. I wanted a cheaper simpler answer. After checking my sources it seems the price of the factory unit is high for the same reason the radiators got high priced. It seems that although the other versions of the actual electric motor made by Bosch are available separate from the cage and housing ours isnt. I spent several hours researching the part number stamped into the Bosch motor in our blowers. It doesn't seem to have a cross. I did find several that were close. So I ordered one and compared it. What I found was an almost exact match but 1\8 longer can. This is where my project begins. I will post pictures tomorrow. I'm in testing of the unit and am very excited. Hopefully the longer motor will spin that cage faster and blow more air.

Rob Edwards

Does your replacement look like the one in this thread? If so, make sure you attend to the wiring issues raised by Greg in post #43:

https://rennlist.com/forums/928-foru...placement.html

Mrmerlin

before you get too far,
Roger has sourced a plug and play, brand new motor, its quite reasonably priced

Captain_Slow

You're following in Roger's footsteps. I bought the motor and wiring harness from Roger. The harness is designed by Greg Brown and built by one of his apprentices. Very high quality.

At Frenzy I spoke to Greg Nichols about my replacement job. My fan cylinder was wobbling on the shaft and contacting the plastic housing (sounds like yours could be, too). He fixed his by replacing the fan shaft bearings. He didn't find an exact bearing match, so had to make some modifications on a drill press IIRC. I think the bearing he used was slightly larger than the originals. I did notice that the only problem with my original fan motor was the wobble in the shaft...at the bearing(s).

It is nice to have a brand new motor -- and it's a higher output motor. Blows very strong on the highest setting. If your recirculation flap actuator (in the passenger footwell, inside the recirculation air box beneath the blower motor) isn't working, now is a good time to replace it. Not a fun job, but not difficult and well worth the effort.

sstrickstein

Yup following in his steps... Just Goes
To prove most things you can think of have been done before. Still testing but I wondered about the heat issue. After reading that post was figuring Id need something. I started with a spare housing. I'm going to test run the rig today on a 12 volt battery jump box for several hours to test.

Jetdriver69

I give a huge for the Roger blower motor retro fit.

It was easy to install and works great. Super quiet compared to my old noisy unit and blows twice as hard.

I did take the hood off to make installation a bit easier. Took about 3 hours with the hood removal/install.

sstrickstein

I'm running my fan assembly on a jump box with test leads right now. After 1/2 hour that pig tail from the motor to the plug is warm to the touch but no hot. This fan not is kicking out way more Than I remember last one doing . Strangely the wiring after the plug is cooler that the pigtail wires. This leads me to believe that there is resistance in the old wires and that may be a source of problem. I may make a new pigtail

Tazzieman

I went the (new) ($50) Passat motor route which required slight modification of the housing , but no wiring mods. After a full summer (my AC is non-functional) it's performed faultlessly and the wires have never got hot.
But as usual there are several ways to skin this cat!

kmascotto

Mine was starting to vibrate, so I pulled the motor and took it to the same guys who rebuilt my starter and alternator. They had a new bearing machined (The source of the vibration) on top of the standard rebuild items. $160.00 later and its works like brand new

sstrickstein

I used a motor out of a Mercedes-Benz 560SEC. And I too modified the housing. My tests did not reveal any perceptible wiring heat issues yet. I will next install the assembly and do more testing and checking the wiring.

ROG100

My goal was to find a motor that would fit without modification that would also supply a higher volume of air.
My motor fits the later blower case - approx. 85 to 95 without mods. Earlier cases need minor Dremel surgery to fit.
The motor supplies about 25% more air than a new original but in doing so draws more amps - hence the additional harness that draws power from the jump post to the blower and is triggered by a relay.

The more solutions the better.

sstrickstein

Roger how much would you want for just the wiring harness

ROG100

The wiring harness is $125.

sstrickstein

I installed the reconditioned blower motor and a recircula door from mark at 928 international. It will be good come summer here. I'm gonna keep an eye on that blower motor harness and if I need it I'll get that harness from 928srus. There was a large nest that was wedged in that I pulled the recirc door out.

sstrickstein

With several weeks of use under my belt I can say all works great. No problems with the wiring. Air volume is great! So the motor I used was from a Mercedes Benz 560Sec. The bosch part Number for this motor was very close to the one I pulled out. The only difference I could tell was the body of the motor was about 1/8 inch longer. My modifications to the blower motor housing were very simple.where is the head of the blower motor sat in the housing near the brushes I ground some braces out to get about half the distance. The other side or cage side of the housing had to be modified as well. I opened up the mouth of the blower motor housing by about an eighth of an inch so that the vanes of the blower cage would not hit it. The combination of these modifications made this Bosch motor work well and increase the volume of air flow.I will continue to monitor my wiring to make sure there's no bad effects however I would say that with this blower motor it seems that it works just like the factory.