R129 Blower Motor - PeachParts Mercedes-Benz Forum

nt-j · #1 05-21-2006, 12:08 PM

Hi everyone,
This is my first post to this forum.
I have a 91 SL500 fitted with climate control. The problem is that the blower will not work.
Last year it was intermittant mostly O.K. but after a short rest would run.
I laid the car up for 5 months, on starting it would not run at all, took it to specialist who freed it and lubricated bearings, also the centre hot air face vent switch was stuck in preventing anything from working !
On getting it back it was O.K. for a few weeks except on speed 4 but now has stopped working alltogether.
Can anyone tell me how to get at the fan to check it out. ( They wanted £180.00 plus fitting for a new one ) also bought a CD Repair kit off e bay, absolute rubbish, got my money back.
N T-J

Carlos Serrano · #2 05-21-2006, 12:56 PM

In my R129 The motor is buried deep under the cabin filter, open the engine compartment, behind the engine, between the firewall and the windshield is your filter cover.
I took mine to the shop, the blower regulator was burned up due to the squirell cage rubbing against the housing, the plastic clips broke off, replace entire housing, regulator and labor. $ 800.00 USD.
Good luck with yours

#3 05-21-2006, 01:55 PM

Quote:

Originally Posted by nt-j

Hi everyone,
This is my first post to this forum.
I have a 91 SL500 fitted with climate control. The problem is that the blower will not work.
Last year it was intermittant mostly O.K. but after a short rest would run.
I laid the car up for 5 months, on starting it would not run at all, took it to specialist who freed it and lubricated bearings, also the centre hot air face vent switch was stuck in preventing anything from working !
On getting it back it was O.K. for a few weeks except on speed 4 but now has stopped working alltogether.
Can anyone tell me how to get at the fan to check it out. ( They wanted £180.00 plus fitting for a new one ) also bought a CD Repair kit off e bay, absolute rubbish, got my money back.
N T-J

have you inspected the fuse for the unit? i have seen some crack and cause intermittant operation, the fuse however would not account for the high speed being inop. on US modes the fuse is a strip type fuse under a black cover located above the brake booster, should be a 30 amp type, see picture below.

TheV12pwr · #4 05-21-2006, 03:34 PM

Blower motor regulator is blown.
$380.00 best price I could find.

mikebrou · #5 05-22-2006, 03:21 PM

thankyou so much for your reply , will check it out, mike

nt-j · #6 05-23-2006, 12:45 PM

Thanks for your replies.
Had checked fuse, appears O.K. but will put a meter on to see if there is voltage.
Tried to access codes through climate display, could not get any to show up, the only thing I managed was to do the reset the codes. I suspect the display controler might be faulty, I have always had to press the buttons more than once to get it to work properly.
N T-J

tecqboy · #7 05-23-2006, 08:36 PM

If you do a forum search on the climate controller, I believe you'll find a lot of info regarding it's primary failure problems and their fixes. I think one of the biggest problems is that solder joints of the switche's are prone to becoming cracked ( on the printed wiring board ) and thus intermittent. Lot's of good info in past posts. Perhaps your blower motor is OK and the controller is at fault.

jjrodger · #8 05-24-2006, 03:45 AM

It sounds to me like your blower motor regulator is blown.

However, check the 30A fuse at M2 in the under-bonnet fusebox.

I had a new blower motor fitted earlier this year (mine worked but made a noise like crickets in the dashboard). The cost was relatively reasonable given the amount of labour involved. I think the dealer failed to appreciate when we agreed the price that you have to remove the windscreen wiper system to get at it!

nt-j · #9 05-25-2006, 12:20 PM

Hi tecqboy,
Thanks for the info, will try and find the threads.
Have just bought of e bay the later version with the big screen the seller assures me that with some wireing mods it will work !!, he is to e mail me the diagrams, it could be an interesting weekend !!
N T-j

nt-j · #10 05-25-2006, 12:24 PM

Hi JJ,
Thanks for reply, mine was not noisy when it worked so it is most likely the regulator or the display the fuse is OK.
Did not realise I had to take off the wiper motor as well !!
N T-J

nt-j · #11 06-04-2006, 08:17 AM

Finally got to the blower motor - it was seized solid. Took it out and freed it & will lube it properly, the controller appears O.K. on test with four different Volts on the output 7.5V, 10V,11v & 12v hope this is correct.
But have found futher problems, the long two section flap fitted above the blower & controller was not working, one side the link was broken and on the other side it was not even fitted !! also the flap that feeds air to the top centre vents was totally missing alltogether !!
Somebody has done a complete bodge job. I am going to have to source some prts if possible.
N T-J

jbach36 · #12 06-16-2006, 10:23 PM

I have a '91 300d with the normal a/c blower problems that Mercedes has sold to us for years, and live in denial that there's a problem.

A diagnosis said the blower or blower module is bad on my car. I took both out, the blower looks fine. But the module?? There are no moving parts on it. How could it go bad, and how can you test it? How long should they last? With no moving parts, it seems as though it should last the life of the car, but they found a way to make them fail. Is there anyway to repair the module?

tecqboy · #13 06-17-2006, 10:41 PM

The electrons in there are all moving at nearly the speed of light. When too many of them try to move through the same piece of silicon at the same time, the silicon melts and the device fails. One always hopes an aluminum fuse will melt first, but in my experiece, it's always the most expensive part that fails first.

nt-j · #14 06-19-2006, 09:23 AM

Got it all back together a couple of weeks ago. The blower will still only work on speeds 1,2 & 3. 4 has no effect even with the controller giving 4 different ouputs. Must be the controller. Managed to repair the main flow diverter above the fan but not able to locate a flap to control the top vents, at least I can get cold air in the footwells.
Does any one know if the Unwired Tools modification will work on the R 129 ? I sent them an e mail but no reply yet.
N T-J

Daberg · #15 07-04-2006, 01:21 PM

Thanks to everyone for the ideas, I'm new to this forum stuff but it is a great way to exchange info. I have a 91' 300SL and I am having the exact same problems

The blower has never work I'll owned this one for about a year. I also had similar problems with a 86' 420 SEL that I previously owned. You can feel the temp changes at the vent but the fan won't blow. I did check the fuse but the one that I saw in the forum doesn't look like anything that I saw in my fuse box unless it's in the trunk box! I will check there as well. How long does it take to get to the blower motor and regulator on this vehicle? Thanks again to everyone for the info, I will periodically check forum to see if there is any usefull info that I can provide.