I just picked up a 240D that has a blower motor that works intermittently. It will run for a few minutes and then go out, maybe come back on ten minutes later. Setting the fan at medium has had the most success. Heater core is fine. AC is non-op. Could there be a loose connection somewhere? If I have to replace the blower motor, where might I find a good manual or DVD demonstrating the procedure? Thanks,

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'81 300SD

Otto,

I recently acquired a 240D too, so I know where you're at right now. The first thing I would do (and one of the first things I did do) would be to replace all of the fuses. Mine had the plastic body fuses which should really be replaced with the ceramic body type. Even if the fuses look fine they can be bad or going bad. The ends thate contact the terminals also get corroded creating resistance. That may not be your problem, but I would start there before proceeding with anything else - new fuses and clean the terminals if they look even slightly corroded. Good luck.

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'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
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"Back off, man. I’m a scientist” ~ Peter Venkman

super easy to replace blower: pop off passenger kick panel, you'll see the housing for it. then either unscrew or unbolt three screws or bolts (8mm), unplug the wiring, and pull it down and out. on some models there's a heater core tube that's insulated, running right along the bottom of the blower motor, so you need to jimmy it out of there. also there was at least three kinds of blower motor for w123, be sure you get the right kind

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Mine would only come out through the glove box. Send a pic to the salvage yard if you get a replacement. I've sent one back because it was wrong. If you pull it, you may find worn brushes. I got some at a starter shop, sanded them down to fit. If it's not working and then you smack the blower and it works, prolly brushes.

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CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

Just curious, It was your Euro's blower that had to come out the glove box? I have heard the Euro's are different but haven't had to deal with mine yet. All the other 123 blower motors I've seen have been easy to fix and just drop right down.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Thanks for the reply's fellas. I'm relieved to read that this isn't a huge job. I thought that the heater core and blower motor were in the same ballpark in terms of difficulty.

Tankowner, I'll probably send you a PM sometime soon regarding your shut off vacuum issue. I'm going to test the ignition switch today. Solenoid is good. Thanks,

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'81 300SD

I look forward to it. Not have much time the past few weeks I really haven't seen to it. I went ahead and order a new vacuum switch (hasn't arrived yet), but I am still very interested in learning more about its proper operation. Thanks!

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

Yeah, AC evap line gets in the way of pulling it down. Pull the glovebox, latch & light, twist & pull here & there. Impeller diameter & depth, motor housing & connector were all different than what came in the mail. Bit of a frankenbenz, it came to me w/ a 616.916 instead of a .912.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

Thanks for the heads up, I've not needed much except "maintenance" items for my "85" Euro, but I spoz the day will come that I'll need something thats a special order, Euro part

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Run a power and ground from your battery to the prongs on the blower motor where it plugs in... if it's ok, it'll spin right away.

That's where I'm stuck at on fixing mine.. tested the motor and it worked perfectly.... and swapped in another HVAC head that's SUPPOSED to be functional (from a friend of a friend of a friend) and I still don't get the blower to kick on.

The control head clicks and I hear the valves working when I hit the switches, and I'll get ambient heat from the vents when in motion, but that's it... not a chirp from the blower motor..


Is there a resistor or something between the control head and motor?

My '83 300 Euro had a/c installed when the p.o. moved from Germany to California. The dealership did the install, and really didn't do a very good job - one of the lines from the compressor is located directly above the oil filter housing. Makes oil changes WAY more difficult than they should be.

I've often wondered if they had to use some sorta' funky blower/motor when they installed the a/c?? Maybe it is just a different part? Maybe I should look it up on the EPC? I'll try to remember to do that next time I have it pulled up.

Jay

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On the road, currently:
'83 300D (German spec.) 168k mi. - - Wolfgang (tucked snugly away for the winter!)
'87 300D 375k mi. - finally went over to "The Dark Side"
'87 300TD 225k mi.
Cannondale 66cm CAAD5 w/Campy/Jamis Aurora
Hujsak Custom Fixie/Landshark Track Shark Custom/Ahearne Custom 29'er

I wonder if you might be having problems with the traces on your CC unit. Now, the odds of it happening on two CC units...
I've not had this problem yet but there is a thread that discusses a resolder of the circuit board on the CC unit.

Throwin a bone,
Codifex
1981 240D ChinaBlue (found an engine - hope it's good)
1983 300DTurbo w/sunroof

Hello, I am having the exact same problem and am on my third blower motor and second ccu.????1980 300TD.

Where is the monovalve located on a 1980 300TD? I think mine has been removed cause I can't find it. Ihave a molded bracket with two holes on the firewall close to some heater core? lines coming out of the firewall but they are just connected to some short hose that bent back towards the firewall? I would think someone has bypassed the monovalve on my car but these hoses look like factory bent little hoses ....unless there is a kit that comes with these bypass hoses??

Nevermind, I got it working again. I feel a little better now. I used the DIY section to resolder all the connections on the four boards that I could access on the CCU. I even resoldered the fan switch and the temperature wheel. I used isopropyl alcohol on a q-tip after soldering to clean it up even more and the boards look brand new and shinny....I think I may have got to every availible solder.

Under my own addmition When I first put the REBUILT CCU in, it did not work... so, I checked the fuse. It was burnt.....and that may have been the cause all along this time, which was dumb but I can't help but think I'll be better off having done this anyway. I did check the fuse a while back but it looked o.k.
I had the small glass tube style fuses and the filament looked o.k but the solder had melted in the silver end caps and upon removing the fuse from the holder there was a bit of a burn mark and some solder from the fuse on the contact spring holder.Thanks
I guess for myself anyways... special mention to tankowner from post number two on his advice. I should have checked that fuse holder/contact thing first a little bit more carefully. My repair was on a 1980 300TD.

Also when there are problems with the blower motor, a thing to consider is the magnetic commutator brushes that DC motors use. All you have to do is clean them sometimes(unless the magnetic brushes are all worn out). Sometimes they get stuck and dont make contact, which often will result in intermittent operation. If you take the blower motor out, and take apart the motor part of it(cant remember the setup, but it wasnt difficult at all) you will see magnetic brushes. They look like little blocks. just clean them and clean the housing.