blower motor or regulator? and difficultiy

[Johnson Chan]

Hello Everyone,

This is for a 1992 300D 2.5 turbo (124). Here is the deal...

I took the car to the dealership because AT IDLE, there is no blower motor movement. BUT WHEN DRIVING AT FAST RPM (i.e. highway) the blower motor will work.

The dealership quoted $1200 and said both needs to be replaced. I asked which one is bad, and they dont know because you have to take the windsheild wiper motor out to properly diagnose the problem and it would cost $500 bucks (just diagnose the problem)

So should I replace both or find out which one is giving me problems and replace just the one.

1) I did a search on the subject and nobody really talked about how long it takes or any difficulties they encountered.

2) I changed the blower motor fuse and cleaned the contacts, but no help.

3) last winter i heard some squeeling noise from the dashboard area and when i turned off the heat system "O", the noise went away. But it worked fine and didnt make any noise over the summer so i just left it alone.

So... where should I start?

[jc300e]

5 hours labor to diagnose !!! Wow!
I just replaced my blower motor assembly. I'm a below average DIY'er and it took me approx 45 min to remove all the parts to expose the blower, 15 minutes to remove the blower and about an hour to put everything back. I took an additional 30 min to clean out the blower compartment, damper and coils before installing the new blower.

I paid roughly $240 for a new blower.

If you are thinking about DIY'ing it, do a search on the site. I know there are several threads that give tips.

In general, perform the job when you are calm, unstressed and able to work without distraction. It's not hard. There are just a bunch of trim parts, tiny screws, etc...

[GermanStar]

Just goes to show that, in general, you shouldn't take an out-of-warranty Mercedes to a dealer for service. I can tell you that the blower motor is far more popular (to the tune of about 25 to 1) than the blower regulator.

Ron
http://germanstar.lnet

[Johnson Chan]

Thanks for the reply.

Do you think a bad blower motor could cause the problem I am describing? I dont want to "throw parts" at the problem. I have read on some thread that there is a 3 prong connector near the firewall that you can test to see if its getting 12 volts but I have yet to locate this prong.