Hi! I realise there are a lots of threads about removing blower motor/regulator and all that fun stuff. I'm just wondering if there could be anything else before I start what seems to be hell of an operation.

In short:
1990 w124 300E
Automatic clima (the one with all the buttons)
Have had some squeeks in the blower motor during cold weather
Suddenly blower not working at all
Regardless of all settings max/min, auto, defrost, nothing

Everything else electrical seems to be ok (except everything that didnt work earlier also)

I can hear a relay clicking when I turn the temperature wheel.
Checked and replaced the fuse for the blower motor (12)
Pulled the relay behind the battery which says klima, put it back
Looked at the big metal strip "fuse" on the left side of the engine bay, in front of the fuse box.

Cant be nothing but the regulator - right? I am reluctant to start, but it is basically a straight forward job isn't it? Is there a way to make sure a have a correct replacement regulator before I start? I dont have anywhere to work on my car so I have to put everything back together the same day...

Thanks in advance - and apologize if this is covered somewhere else or if this is the wrong forum

Lars

Sometimes the strip fuse develops a hairline, transverse crack. Remove the 2 screws that secure it in place and check that it is not cracked.

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Fred Hoelzle

X2 on what Ferdman said. Either check the strip fuse with a meter, temporarily jumper it or replace with a new one.

Likely blower has failed. Do check fuse as mentioned. Mine was fine. My blower failed and was squeaking in the last few days of operation. The job isn't hard just follow the tech article with our host PP. Also grab some new cabin filters and since you will be removing the wiper assembly recommend cleaning and renewing grease lubrication of that unit at this time. Good luck.

Sadly no cabin filters on the pre-facelift cars. As the others have said it's not a difficult job just time consuming. I also agree on taking the opportunity to clean and lube the wiper assembly. It will never be easier to do than when you have the whole thing apart.

Start in the morning and you should be done in time for lunch.

Thanks for tips. Update:

Pulled my heater motor and it wasn't too bad of a job. Found out that the motor was almost seized. I lubed it and it seemed to spin well after that. i wasn't able to find out how to get to the regulator.... It put the motor back in and everything seemed to work pretty well. Hi, low and auto works - maybe hi speed wasn't really fast enough? Not sure about it.

However a few weeks later after filling gas and starting the engine again the fan was dead again.

After that it suddenly started working again a few days later - everything seemed normal. Has been like this for the past couple of weeks. Works normal for a while, suddenly stops working, but starts working normal again a few days later. Very bizarre.

Must be electrically related. Some sort of relais? Or simply the regulator - can it behave like that? Any tips would be appreciated!

If you have to dive back in there I'd suggest replacing the fan with a new one, or a low mile donor. It's likely the brushes are worn in yours. The blower regulators can go bad, but I think when they fail it's a complete failure. Maybe someone else can chime in with actual experience.

The regulator is mounted under the cradle that holds the fan. The facelift cars use a different regulator, so be sure to get the correct early one if needed.

Update: regulator is dead. There was 12v between the red and the blue cable so I assumed it was ok, but when connected to the motor it drops to zero v. Ok, a little bit more than an enormous hassle to get it out. Working on getting a new one now. Roughly $700 for a New one here in Norway(!!!!). I have found some China ones on EBay. They are a bit different- the cooling pins are much shorter and fewer, but the corresponding part number is the same. Anyone tried these? Mine is a Bosch/behr. Part number 1248202710

larsko, recommend avoiding anything made in China, unless you want to repeat the job in short order.

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Fred Hoelzle

Thanks - i try to do that (avoid)

I'd try to find a used OEM part if I were you. Again, be sure you get the correct one. It's kind of triangular in shape. The later ones are rectangular and will not work.

I've had good luck with an ebay special, been two years now and it was ~$30. The original is seriously jammed in there, be careful it's frustrating. Aftermarket regulator is smaller so it slips in place much easier.

You can also bypass the regulator a number of ways, try searching the forum.

Had some luck today. Found a regulator from a w202.everything look different except the very electronic component inside the black plastic casing - it's exactly the same one as on mine. Will try to solder it over tomorrow - wish me luck

Update - was able to solder on the new regulator to my old harness today. Takes a pretty strong iron to do it but I guess it was ok. Plugged it in a tested it on a "new" motor from a late w124 - smaller diameter from mine. Plugged it in and it ran full speed all the time. Reckoned the regulator was bad after all and said some nasty words. Then for some reason, I had the idea I should test it with my old (almost seized) motor. And it spun in different speeds. Ok - regulator works. Hurrah! Need to look for a new (similar) motor tomorrow! Regulator is back in the car - much easier getting it back in. I have connected an extra set of long cables so I can test motors directly without having to take anything apart.

Here are the two regulators
Old one - 1248202710 at the top. New one 9140010153 at the bottom. New one had only 4 cables but was made for 5 - one extra red cable
https://www.dropbox.com/s/v0q38owadbny5qj/File%2003.08.2016%2C%2023.28.13.jpeg

Finally everything works. Was very lucky to find an almost unused motor today at a mb dealer which is closing down. https://www.dropbox.com/s/j6o6b6a7wuldk8n/File%2004.08.2016%2C%2019.59.58.jpeg?
Put everything properly back together. Spendt the most time putting the stupid rubber half moon around the wiper in place. Kind of tricky to get it right.