I'm working on the blower for my 300D (W124). Not sure where to go next.

Installed new blower, tested OK before install, now nothing. Fuse is good. This is the second blower in 6 months - installed a used one previously, now this one.

Where should I look next? The push button unit works as I get A/C and heat, and control deflection, etc. Just no blower unless I'm going 40 mph, etc.

Any help appreciated, thanks.

Doug

Your "now nothing" means your blower burned itself?
What happens with your used one. It get burned too?
"Just no blower unless I'm going 40 mph" means it get on after 40 MPH?

If you apply 12V direct to the blower, does it works?
If yes, disconnect the plug to the blower. Do you get 12v on it?(car's plug) (pushing the "max" button)
What about the relay?

Start with this. Let us know.

Thanks for the reply.

I'll have to check the relay (where is it....???). I get ambient blower when over 40 mph or so. It's not really the blower, as I know you all know, but it acts as such when speed is up.

12V directly to the blower .. the blower works fine. I'll also check voltage to the plugs, haven't done that yet.

Doug

I have read here that the problem is sometimes with the ignition switch. In this case, you would likely get around 12v at the plugs, but the fan would still fail to operate reliably because the switch is unable to handle the load (meter would drop to Zero volts under load if you were still measuring).

A 2nd hand solution, but perhaps worth checking out.
Best of luck.

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1986 300E 5-Speed 240k mi.

If your car is like my 89 420 sel, it is the blower regulator. . .$400 from Mercedes, $20 from salvage yard.

Dwight

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Dwight