Climate control fan - PeachParts Mercedes-Benz Forum

300TD · #1 05-28-2006, 11:34 PM

Today my fan finally quit. It has been acting up for the last few weeks. It would work fine if the car sat overnight or a lone time during the day but would sometimes fail if the car was turned off and re-started a short time later. Yesterday it started out fine but seemed to go slower and slower until it finally did not work at all. Checked the fuse - OK, switched the fan speed controller to another one I had - still no fan. I know there is probably an answer somewhere in the threads, but I could not find it. Any help would be appreciated.

Thanks

MBeige · #2 05-29-2006, 05:00 AM

Mercedes Source has a kit to sell if your blower motor brushes are gone. My dad and I just finished this and that saved me $50 since a new motor would be $80.

The brushes had "H557" on them I believe. You'll need two. I'd love to recommend Kent Bergsma's kit but I think it's too costly ($30).

"If you think it's worth it, it is." would be a good phrase. Now both cars have functional blowers. The wagon seems to only need recharging of R12 and that's (hopefully) all it needs.

I'd love to do a write up but I don't want to plainly copy Kent's instructions. We didn't exactly follow his method because the motor brush bracket/end was hard to remove from the armature without the possibility of destroying the 8 tabs, so we just did invasive surgery using a 25W soldering kit we bought and some creativity.

Basically:

Remove underdash panel (3 screws under 3 tabs + 2 plastic screws on each side)
Remove three 8mm screws on blower housing plus 1 philips screw in the front part of the blower
Unplug blower and remove blower from car
Clean well (lots of dirt from 23 years of service)
Remove tab that holds plug covers
Undo plugs and remove blower cage from blower base using a 7 or 6mm screw
Undo the tabs that hold the springs for the brushes, be careful of springs that will shoot out (1 on each brush)
Solder brush wires until they're disconnected, match length to new wire on new brushes
Solder new wires in along with brushes, taking note of brush orientation on grooves
Reinstall spring into brackets and gently tap the tabs that hold the spring back into place to hold the springs
Reinstall blower motor + blower cage unto base
Reinstall entire blower assembly (cage + motor + base) into car

300TD · #3 06-06-2006, 08:28 PM

Thanks for your help! Just replaced the fan with the spare I had in the garage. It was new when the old car was totaled. Works great again!

Thanks again!

peragro · #4 06-07-2006, 12:31 AM

While the old fan is out it wouldn't hurt to change out the brushes for the next "swapover". It's not hard to do, even if you're not good at soldering, like me. I agree with mbeige, you should take the old brushes to an electronics store and see if you can find a match - much cheaper that way.

Jeremy5848 · #5 06-12-2006, 11:38 PM

Quote:

Originally Posted by MBeige

... a new motor would be $80....

Where are you getting motors for $80? Phil's current price is $169.74.

I removed the fan from my 1985 300D Turbo (thanks for the instructions) and was amazed at the amount of wear on the commutator. Even with new brushes, I would say the motor is almost gone. I may take it to an auto electric shop, see if I can get it rebuilt.

H-townbenzoboy · #6 06-13-2006, 12:11 AM

Quote:

Originally Posted by Jeremy5848

Where are you getting motors for $80? Phil's current price is $169.74.

That's the ********az price.

Jeremy5848 · #7 06-13-2006, 12:29 AM

Quote:

Originally Posted by H-townbenzoboy

That's the ********az price.

Thank you. Now $85.33, by the way, but still the least I've found.

OMEGAMAN · #8 06-13-2006, 11:29 AM

Someone suggested going to a vacuum repair shop for new brushes. I did this and got a pair for $7. They were slightly too large so I filed them down in a few minutes and they work great.

Jeremy5848 · #9 06-13-2006, 04:51 PM

Has anyone had experience removing the plastic squirrel cage from the metal motor shaft and pressing it onto a new motor? I'll probably end up doing that later this summer and would prefer to not break the cage in the process.

Jeremy

tangofox007 · #10 06-13-2006, 04:58 PM

I supported the fan on a couple of boards (one on either side of the shaft) with the motor suspended beneath. Then gently tapped the shaft out with a hammer and pin punch. Small hammer recommended.

Jeremy5848 · #11 06-22-2006, 01:18 AM

As I continued to examine the motor in my fan, I saw more and more how much the commutator had been worn by the brushes. Even worse, the groove was uneven, much deeper at the bearing end, where the commutator metal had been cut almost completely.

Although it would still be possible to install new brushes and get a few more miles out of the motor, I reluctantly decided that my time would be better spend on my leaking half-axles (but that's another thread). Accordingly, I gave up and ordered a new motor from ********AZ for $85.33 and free shipping for orders over $50.

Thanks for the advice on removing the plastic squirrel cage, Tangofox. I shall endevour to tap gently with my smallest hammer.

Jeremy