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Bakervo 07-16-2003 12:20 AM

A/C Not Blowing
Okay, I need some suggestions. My 1986 300E does not blow cold air. The A/C is cooling, but nothing comes out of the vents. This is what I've already done to remedy it:

- Changed the Climate Control Unit
- Check the fuse in the Fuse box
- Checked for external fuse, but it appears my car does not have one, or at least it's not mounted to the strut tower
- Changed Blower Motor and regulator

I still can not get it to blow anything more than faint air. Any suggestions would be greatly appreciated. I'm quite frustrated at this point.


joe p 07-16-2003 07:48 AM

The push button panel provides the signal for blower control, is it stepping to high speed? Close to 7v signal for high blower.


stevebfl 07-16-2003 07:56 AM

The signal wire is easily monitored at the three wire connector on the fire wall.

Bakervo 07-16-2003 04:21 PM


I'm sorry, but appologize for not comprehending. I'm not sure what you're asking or recommending I do.

Please put it in simple terms for me.


stevebfl 07-16-2003 07:52 PM

Since you have been inside everything I presumed you knew what everything was doing.

The blower regulator connects the negative side of the blower motor to ground. The possitive side is switched by the key and always battery voltage.

Check blower positive, is it 12+v. Check blower negative, it should be between 6v and almost zero volts. Theoretical would be zero at high blow. Hook your blower negative up with a jumper to ground and see if it blows. If it blows and you aren't getting air inside I don't know what you got.

There is a three wire connector on the firewall that allows some of the testing to be done without total disassembly. Must has been writen in the archives about this testing. I wouldn't think of doing this without a wiring diagram. If not, I might wind up buying a blower and regulator and a bunch of not needed parts.

Bakervo 07-16-2003 10:36 PM


Thanks a lot for the suggestions. I did test the blowers (the new and old one) and they both blow when I apply power.

At this point, I think I have an electrical problem. I will take it to a profressional.


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