The problem is the blower motor runs .. but no air comes out of the vent.

I am having the same problem. I just purchased my 84 300SD and it never worked since I purchased it. I can feel the heat or the a/c coming out of the vents but no blowing action. Can anyone help. Next, if you can help, i dont know where any of the parts are to fix. THanks

I too am having a major AC problem. We have a 1991 350SD with 80K. A few weeks agao, the AC was not blowing. Then, out of the clear blue sky, it started right up. Today, my Mother in Law started the car (I say she did it) and the AC was not blowing. I pulled the car apart, and checked the blower motor. It has power, and I bench tested it real quick, and it clicked over (did not do it long enough to make it turn. I then took apart the rest of the car...thinking it was the fan switches with a loose conenction...NOPE! My brother in law sent 12V to a pink wire that plugs in to the rear of the Temp Dial. The Blower motor clicked each time he touched the power..but never actually turned.

Can this be the Brushes everyone is taking about? I live in So Cal, and it has been really hot..the wife is not happy....Help...

the motor on bench.
You must run it up to speed.
Be sure the motor bushings are well lubed, and NOT sticking/binding = spins free by hand.







Have a great day.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

Ok...my blower motor spins freely, and the brushed seem to be good and making contact. When I say freely, it does not spin on its own, and needs asssitance, but it spins. I decided to put the blower motr back in and plug in the Blower Motor Regulator "porcupine". I turned on the AC and the blower motor was working fine..the air volume was low, but that is becasue everything was open...When I had the fan speed on Auto, the fan turned fast, on low, turned low (barley moved) and on high it turned fast.

Once the porcupine warmed up, the fan speed got slower and slower. Then finally the fan stopped turning...and the porcupine was super hot..could not even touch. My thought is the Blower Motor Regulator is bad? Help...any ideas, thoughts...anyway to test that or bypass it to test the fan?

There are 3 wires on the regulator-think pink wire, a thicker guage brown and a thicker guage green.

Help..need ideas..thoughts...Thanks...

Hope a member has a good used one for you.

Vehicle 1991 Mercedes Benz 350SD

Fastlane: Blower Regulator, Behr-Hella, Note: Sometimes Referred to as the "porcupine".
http://catalog.peachparts.com/item.wws?sku=W0133-1598146


Blower Motor Links Page
Blower Motor Links Page