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A/C blower motor not blowing

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Old May 24, 2004 | 02:08 PM
  #1  
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S320
A/C blower motor not blowing

Another blower motor question. I have searched and found a few posts that address my problem but want to be sure before I dig in. '95 S320 W140 with 86K miles. I recently had AC recharged. The blower motor is intermittently working. The compressor is working fine and when the blower doesn't blow; you can feel the open window pulling cold air slowly out of the vents. Again, sometimes it will work for a block or a few miles and then just shut down. I have read that it might be the blower regulator on top of the motor but would like reassurance before ordering the part and disassembling the cover under the hood. Summer seems like it is already here and I have got to get this thing working.

Thanks in advance for all replies.
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Old May 24, 2004 | 04:09 PM
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mbtech208's Avatar
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1997 Toyota Tacoma 4x4
It's the blower regulator, no doubt about it.
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Old May 27, 2004 | 10:14 AM
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OK. Parts ordered. I'll let you know how it goes.
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Old Jun 1, 2004 | 11:47 AM
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S320
A/C blower motor regulator - $185
Pollen filter - $ 40

Replaced the regulator and blower is now functioning correctly.

For anyone doing this in the future:

Removal:
The regulator has a connector with 4 pins and 2 lead wires (red and blue). Make sure you disconnect the 4 pin squre connector BEFORE disconnecting the red and blue wires. If you disconnect the red and blue wires first, they will continue to be HOT and could arc if they come into contact with metal - or give you a bad shock.

Installation:
Make sure to connect the 2 lead wires (red and blue) FIRST before connecting the square 4 pin connector. If you connect the 4 pin square first, the red and blue wires will become HOT and may arc if they touch any metal. Again, connect the 4 pin square connector LAST.

Other than that, it was a piece of cake as long as you have the torx bit for the majority of the screws. Thanks for the help in getting my A/C working again.
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Old Jun 7, 2004 | 09:31 AM
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CLK 500
I am having the same problem with my blower. I would like to know where did you get your blower from? And is the A/C blower the same thing as the Heating Blower Motor. Thanks.
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Old Jun 7, 2004 | 10:24 AM
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I got the regulator at demandparts(dot)com. They have a Behr unit for substantially more $$. I got the KAE one and it looked just like the one I took off and worked fine. Make sure to read my follow-up post about the wiring before doing the job. They have free shipping for orders over $50 and they shipped promptly. Very satisfied.

Yes, I believe the same blower motor pushes air through the vents both heater and A/C.
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Old Jun 8, 2004 | 05:20 AM
  #7  
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CLK 500
Thanks for the info. From reading your post, i think my car is having the same problem, and i went on Demandparts.com and checked the blower regulator that you recomended. Now the only thing confusing me is that do i need the Blower Motor too or no? How do i find out that my problem will be fixed just by changing the Blower Regulator and the Filter, and I dont need the whole Blower Motor itself.
Just to give you some info, when I drive the car and turn on the A/C, i can feel the air, but its very slow barely even noticable, and keep in mind that I have the control to the MAX. So you still think i just need the Blower Regulator and the Filter and not the Blower Motor too. Thanks in advance.
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Old Jun 8, 2004 | 03:17 PM
  #8  
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S320
Yes, I would think just the regulator. Mine did the same thing. The faint air you are felling is just the minimal air flow through the intake duct under the hood while the car is in motion (air rushing under the hood). You probably don't have any flow at all when the car isn't moving. The thing is, there are no guarantees when fixing yourself. Risk to reward ratio has to be considered when fixing things yourself. Chances are high that the blower motor is fine. If you replace the regulator yourself and it fixes the problem, you will be rewarded by saving $$. I'm sure you could hook up some juice to the motor and verify it spins - but you could also fry a good motor if you don't know what you are doing. Look at it like an investment in learning!

Do what I did:
1) after reading posts and believing I understood the process, I disassembled the duct housing the pollen filter, regulator and blower motor.

2) I examined the pollen filter and verified it needed replacing - also verified that it looked like the one I was ordering.

3) removed the pollen filter and looked at the regulator to verify it looked like the one I was ordering.

4) manually spun the motor wheel to verify it would freely spin (ensuring it was not locked/frozen).

5) put pollen filter back and layed the plastic duct cover back in place WITHOUT screwing it back down with the 3,000 screws.

6) ordered the regulator and filter.

7) upon order arrival, swapped regulator and filter.

8) fired up the benz and viola - A/C motor blowing.

9) screwed down the cover with the 3,000 screws.

There are pictures on this site of what the duct, filter and blower motor look like.

It seemed to take a couple of uses before acting normal - like the computer was resetting stuff???

Good luck!
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Old Jun 8, 2004 | 07:40 PM
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'15 S550, '10 E350 P1/P2, '02 ML320
BTW,

Not to be a wise *** about it but the reason that you feel air from the vents when moving is because of the vacuum created under the rear of the car when in motion. There are two small doors (hidden by the bumper cover) on either side of the rear of the car, just aft of the wheel. As the air passes underneath the car, it creates a vacuum in these areas and the doors open, pulling air through the car, if there is an open window or fresh air vent. I believe that this was introduced with the W126 model, not sure if it is still part of the design.

-D
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Old Jun 9, 2004 | 08:03 AM
  #10  
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S320
Nice info. Regardless, I believe the minimal air flow is due to the car in motion and not a weak/failing blower motor. Thanks for sharing that information.
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Old Apr 9, 2014 | 02:56 PM
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1996 S500
Blower motor regulator on 1996 S500

I have same issue with my 96-S500. Faint air and some defrost fucnction while car is moving. Two questions:
#1-Can someone direct me to a part number for the regulator?
#2- If I am correct, the regulator is located under the glove box on the 1996 S500?
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