2001 - R129 Heater Blower not working

[Vintage Racer]

Heater blower stopped working yesterday - control unit shows changes on fan speed when altered and vents are cold, but nothing coming through vents. I have changed the 30 amp fuse in the fuse box (which looked ok anyway), but nothing.

Don't really want to take it to my local MB dealer here in France, as they really do not have a clue (multi franchise set up, more used to dealing with Renault Twingo's). I have also looked at a few youtube videos, but they all seem to deal with much earlier cars (early to mid 90's).

Any suggestions on what the problem may be and how to fix it on my own?

Cheers
Glynn

 

[joderest]

I think there is an item that controls heater motor speed (rheostat ???? ), known on a lot of cars to fail, or could be the switch. I suppose the only way to test is unplug heater blower connection and give it a direct 12 volt feed and see if it works, if no go its the motor, if it goes its the control circuit.

I am sure someone with more knowledge will be along soon.

 

[Blobcat]

I'd be looking at the fan, has it seized - I've replaced a few (non- Mercedes) due to them seizing over time - bearing (or brass bush) failure on the fan motor.