Heater Blower Motor ?

My son has a 1969 220 in which we suspect the blower motor has burned out or seized. How does one access this assembly in order to check the motor? I'm only familiar with older American cars where the motor was under the hood on the firewall but I don't see it so I'm under the impression that it is behind the dash somewhere.

Thanks for any help!

[Mark DiSilvestro]

Phil,
If you have checked the circuit, fuses and switches and verify a bad heater motor, you will have to remove the console (both parts), the AC housing and AC blower, then the heater box and controls and finally you will see the heater fan assy screwed to the underside of the dash/firewall. Some have had luck with trying to free up and lube the motor by going through the air intake below the windsheild.
Some have suggested cutting open the firewall but I think they were joking! I went through this operation 14 years ago when I got my '72 250. It's not as hard as it sounds but very time consuming. Get a NEW heater motor because you won't want to do this twice.

Happy Motoring,
Mark

[ctaylor738]

If you do a search, you will find a number of posts on this, particularly one from Channel11.

As CTH is fond of pointing out, MB dangled the motor from a string and built the car around it.

Good luck.

READ AND GOOD LUCK! Restoring the1974 W114 280 Part 2

[william rogers]

my 74 240D had a burned out fan motor when I bought it .After looking at the work to put a new one in I took a fan motor from a 69 Datsun pick up (very easy to get at) took the air intake cover off removed the burned out motor and squirrel cage fan witch had to be broken to remove. I then made a mount for the Datsun fan motor from steel strap . I then put an Audi squirrel cage from a 77 Audi Fox in place of the MB fan ,dropped in the Datsun motor witch mated to Audi cage then put the strap mounting around the fan motor and attached it with large self setting screws, I used the 240's wiring but replaced the switch (was also burned out)with the wiper switch from the pick up. it has been working fine for three years...
William Rogers.......

[Rackne]

So this assembly is integrated into the MB system? On top of the heaterbox perhaps? I had looked at a BMW dual squirrel cage with this sort of thing in mind but figured it might be an even more difficult solution than removal. But the chilling silence on my heater box posts are begining to get to me as much as the chilling forays out to work on the box itself. Please enlighten us with the warmth of innovation.

[Tom Drew]

I would be happy to copy & send to you the pages out of my 1959-1967 service manual for you that outline this procedure. The 1968-1973 manual does not contain this information. I agree with Mark's above post that you want to make sure that the blower motor is indeed bad before going through this procedure!
You might want to contact Michael Medill of Mercedes Used Parts: http://www.mercedesusedparts.com/
He can help you with the diagnostic procedure to determine if your fan motor is saveable. (Apparently on many of these motors, the bearings simply dry out, and if they haven't been burned out, they can be saved by lubricating and freeing them up) You really want to do this before spending the 40+ hours you will spend replacing the motor!
Just my $.02

Tom Drew

[Rackne]

The fan was full of leaves and turns freely now. I need to replace the filter or mesh or whatever they used to keep stuff out of the fresh air intake. As for the motor I haven't hot wired it yet to see if it will work and its still going to be a beast to get out of the dash cage.

[Mark DiSilvestro]

My '72 250 and my friends '72 220 have a fine mesh aluminum screen under the air grate at the foot of the windshield, Don't know if the '69s had this. If you can't find the original in a salvage yard, maybe some window screening could be a substitute. I've just gone through this fan revival exercise on my friends 220. There should be a 4 wire plug under the hood, at the drivers side of the firewall. The inboard bottom terminal is the positive side.
The other three terminals each ground through the fan switch to give low, med, and high speeds. A 12 volt test probe is helpfull to check power and ground circuits.
Hope this helps.

Happy Motoring,
Mark

[Rackne]

Thanks for the suggestion, window screen sounds good. I've got a 72 280SE 4.5 and the electrical connection is on the upper right of the heater box, I'll check it in the morning.

[Mark DiSilvestro]

I was responding to Phils' 115 body 220 fan question. Yours is a 108 body 280SE.
Sorry for the mixup but I hope I helped you anyway.

Happy Motoring,
Mark

MANY MANY THANKS! Whew.... The tip re: going in through the air intake vent worked like a charm! The upper motor bearing was filthy and gummed up pretty bad from sitting almost 7 yrs.
We attacked it with penetrating oil first which did get it started then it would slowly die down. We then, using a large syringe and a piece of tubing, sprayed some brake cleaner into a cap, sucked it up and dribbled that onto the bearing to clear up any remaining gunk and Bingo! It freed up and turned like new! We then just dribbled a couple drops of lubricant on the bearing and away we went.

Thanks again for all of your replies!

Phil & Chris