Blower motor works when heat is on but not AC
Thread Starter
Newbie
Joined: Sep 2008
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1992 300TE
Blower motor works when heat is on but not AC
I have a 1992 300te with 92k miles. I recently replaced my blower motor. The blower works perfectly when the heat is on but not when the air conditioning is running or in economy mode where I just want the blower on, i.e., no air conditioning. I was wondering if anyone may know the cause. Last summer is the last time the blower worked when in AC mode, and I just replaced the motor. So, I suspect the cause is something other than the motor replacement. Again it works perfectly when the heat is on.
I also have a fuse question. There is what looks like and auxiliary fuse box next to the main with spaces for two fuses. However, the spots are empty. There are also two clipped wires in the main fuse box. I have heard somewhere that there was a conversion to an external box for some fuses on the w124. Does anyone know what the external fuses are for and what amps fuses it should take. Is this box somehow connected to the clipping of the wires in the main box. I have attached a photo of the fuse box and wires.
Thanks, in advance for any advice you can provide.
I also have a fuse question. There is what looks like and auxiliary fuse box next to the main with spaces for two fuses. However, the spots are empty. There are also two clipped wires in the main fuse box. I have heard somewhere that there was a conversion to an external box for some fuses on the w124. Does anyone know what the external fuses are for and what amps fuses it should take. Is this box somehow connected to the clipping of the wires in the main box. I have attached a photo of the fuse box and wires.
Thanks, in advance for any advice you can provide.
Out Of Control!!
Joined: Jun 2003
Posts: 14,362
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From: Staples Center
w211 & w124
Just wondering if anyone has an idea on this one. My blower doesn't come on at all so before I start troubleshooting I figure I would search the forums.
Any thoughts on this?
John,
I don't have those clipped wires in my fuse box (just checked) so don't know what that's about.
Any thoughts on this?
John,
I don't have those clipped wires in my fuse box (just checked) so don't know what that's about.
MBWorld Fanatic!
Joined: Apr 2007
Posts: 2,381
Likes: 29
E
I believe those two are for the theft alarm unless you have another pair of fuses next to all the relays above the fuse box.
http://www.peachparts.com/shopforum/...4&d=1243511924
http://www.peachparts.com/shopforum/...4&d=1243511924
MBWorld Fanatic!
Joined: Feb 2007
Posts: 1,297
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From: Connecticut, New Haven
95' AMG SeeThreeSix
The climate control units tend to fail due to old age and weak/cold solder joints etc. and can be blamed for many weird climate control and blower motor gremlins.
MBWorld Fanatic!
Joined: Feb 2007
Posts: 1,297
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From: Connecticut, New Haven
95' AMG SeeThreeSix
Like I said before, it is one of those three things. You can check your motor by supplying it directly with 12v, however, its a real pain to dismantle the whole wiper assembly just to test your motor. If you motor works you are down to one of two things, your climate control unit or the blower motor regulator. Process of elimination.
I'm not sure what signal the CC unit gives the regulator, but if someone could track that down, the coupler from the CC unit to the regulator is under the hood on the drivers side tucked just to the right of the brake booster on the firewall. (If memory serves me correctly).
I'm not sure what signal the CC unit gives the regulator, but if someone could track that down, the coupler from the CC unit to the regulator is under the hood on the drivers side tucked just to the right of the brake booster on the firewall. (If memory serves me correctly).
