Hello everyone,

I recently rejoined the world of vintage Mercedes (previously had a '75 240D) when I found a '74 230 in fairly mint condition (inside and out). The problems are mechanical. Beyond some carb issues, which is an entirely different story, my main issue of concern is the blower motor, which did not work when I purchased the car (thinking it wasn't too big of an issue at the time- ha!). I've had my mechanic (who was pretty good with the 240D- previously a dealer mechanic), look at it and he got it running again for about 24 hrs. at which point it failed again. I'm going to take it back to him, but does anyone have any suggestions on this front? It seems to be electrical since the motor does turn on. Considering I live in Northern Ohio defrost is a must (not too concerned about the heat aspect of things). Thanks for your help!

I seem to recall that I replaced the blower switches multiple times on my 74 and 75 models because they became intermittient and eventually failed. I also replaced each blower motor at least once. If you feel the blower is ok, then start with the switch, but it really could be either one...

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02 S500
92 500SL
92 400E (Sold)
87 300E (Sold)
83 300D Turbo (Sold)
75 300D (Sold)
74 240D (Sold after 20 years)

I have a ZE-17K kit for a Zenith 175 CDT carb. $20.00 shipped.

I looked at the components for the 74-76 carb, and they are the same.

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1970 280S M130 engine- good runner
1971 250 M130 engine- #2 rod bearing, gone
1971 280SE (blown engine,parts car)
1977 German 280S W116-only 33 years old

It would be helpfull if you could tell us if your car has AC, and what your mechanic did to get your blower working for 24 hours.
AC equipped cars have separate heater and AC blowers, with a vacuum-operated change-over switch mounted above the accelerator pedal to select which blower, depending upon the position of the rotary AC control knob on the center console.

If all switches and fuses check out and it turns out the heater blower itself has died, sometimes it's possible to get the heater blower going by inserting a very long screwdriver or a stiff piece of coathanger through the center dash vent and turn the fan blade, but that's usually only a temporary fix. If the upper blower-motor bearing is stuck, some have removed the cowl-air-intake panel in front of the windsheild to get some lube onto the bearing.
Otherwise you'll need to remove the cowl air-intake panel, center dash vent and heater controls, center console, AC evapoarator unit (if so equipped), and heater box in order to reach the heater blower for repair or replacement. Unfortunately, a new heater blower for these cars was around $400 last time I priced one a few years ago.

To avoid the labor and expense of replacing the heater blower, Some have custom-installed one or more 12 volt computer fans in the cowl air intake. Reports are a weak airflow, but enough to get a functioning defoster.

Happy Motoring, Mark

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DrDKW

Hello everyone,

Thanks for your responses. I have it back at the shop. Here's some more information:

1) it does have air conditioning, but the compressor is currently out (needs the clutch redone) and the AC system is bypassed as you could do on the old cars;

2) my mechanic got it running again by running a new ground wire and replacing the fuse, as far as I know from the bill and what he told me. What was interesting was that I drove the car and it worked until I parked it and left it for a bit, then got back in started it up, the blower motor had stopped, the speedometer light went out, and battery warning light came on (although it eventually went out);

3) thanks for the offer on the carb, but its now running pretty good (still needs rejetted, but its also Ohio in the wintertime-might be to blame). I also think it has a Stromberg, not a Zenith, but I could be wrong.

Thanks again for your help- I'm really hoping it's not the blower motor because I've heard and seen pictures that it is really a pain in the ... to replace the motor. My hope is that it is something electrical. If it is the motor, I might just try rigging it up with the computer fans. Although it will be my daily driver, I always have my wifes car!

Thanks again,
Justin

in the archives. You can use the 'Search' feature, for the word blower.

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1970 280S M130 engine- good runner
1971 250 M130 engine- #2 rod bearing, gone
1971 280SE (blown engine,parts car)
1977 German 280S W116-only 33 years old