My ac blower in my 1985 300D just recently quit. All fuses checked out good, but there is no power to the motor. I do have power to the fan switches. I would like to know if there are any tests that I can do to try to narrow down the list of culprits, so I do not have to chase it down with parts. I cannot drive the car until it gets fixed.

Scott,

After talking to you at the office today, I think the following links will get you started in the right direction. Cover info on the monovalve and the blower relay.

http://www.peachparts.com/shopforum/tech-help/5066-300te-blower-motor.html

http://www.peachparts.com/shopforum/tech-help/10146-chilly-heater-1983-300td.html

http://www.peachparts.com/shopforum/tech-help/11536-infamous-monovalve-burrrrr.html

Not much, but it's a start.

BTW: Welcome to the best online Tech forum and Parts house going.

[Edited by MikeTangas on 02-17-2001 at 12:55 AM]

Mike,

Thanks for the tip. The diaphram was torn, so i think that will fix the no heat problem. BUT, I still do not have a blower fan. Sounds like from what I read in those links, that the push button unit is the most likely culprit. If anybody else has any other tips before I fork over the bucks for a new unit, I would sure appreciate it!

Scott,

Have you checked all the fuses? Not just the ones in the fuse block, but the others in the separate boxes on the firewall. Not exactly certain on the 123, but look on the firewall, right side and see if you have several black boxes. In these boxes are more fuses, just left the top of the box off (one has a screw holding it shut) they each hold two fuses. Two boxes are for the windows, one may be for the radio, and the last could be for the blower (it is for the A/C blower on the 280 [separate blowers A/C and heat for me]).

Could be the brushes are bad, have read about folks simply replacing them. Could be the blower just needs a little push to get started again. Lots of free or almost free things to try first.