95 E320 Blower Stopped working Need help?
 

The blower stopped working on my 1995 W124 e320 Wagon. From one day to the nexted. AC heater still work but no blower.

Where do I start? I have heard horrer stories of people spending $1000 at the dealer and getting nowhere. It is a PITA to drive with no defrost. It is my wife's car and she is getting ready to take matters into her own hands.

Help

henry

check the fuse , it is not with other fuses
i am not sure on the 95 modle but in my
87 300E it is located next to the fuse box. hope this will help

I wish it was that easy. That was the first thing I checked. Any other suggestions are welcome.

Henry

Printed out Sections 83-601 and 83-604 of the mercedes repair manual. Will spend some time reviewing, but by the first look, it is very complicated diagnosis procedure that requires special tools. Any help would be appreciated.

Henry

Well the basics are pretty simple. There is a three wire connection on the firewall that tells most of the story. The story should be that the PBC (pushbutton controller) sends a 1v to 6v signal to the blower regulator. Both this signal and the power pass through that easy to reach connector.

This simple point can diagnose whether the problem is blower regulator/blower motor, power supply, or control signal. Get a wiring diagram and find that connector and make this determination. Depending which area is the problem will determine the next step.

There is loads of info in the archives about this. There may even be a picture of the connector although that isn't hard. The wiring diagram as always is a must.

thanks

I will procede as directed. Still looking for the correct wiring diagram, but i will find it and the aforementioned plug. Thanks for the direction and I will let you now if I have any success.

henry

I found the terminal X64 on the firewall behind the booster. Found it on my 87 300TD also. Removed and reattached the terminal. Not having enough time to do anything, I got in the car and the blower miracleously worked. Drove to my brothers for dinner. when I cme back out, guess what? The blower does not work. Worked fine before. With car running I wiggled terminal X64 with the hope it would work. No luck.

Any ideas what could be wrong? Obviously the blower is fine.

Henry

Here is location of the terminal
 

stand on drivers side with hood open ,, just behind the brake booster on the metal firewall is the terminal. Just push up to remove. Some may have a plastic side catches that you must press while pulling up to seperate the connector.


Luck to you,
DanielW

P.S. do a search for my recent posts on replacing the blower motor brushes on my 124 car. There are many hits that will come up in a search.

Check this thread: Fuse Link

Keep us posted,

Haasman

I will attempt to locate and swap out the electronic blower regulator with my 87 300TD. The manual shows the relay located behind the front center vents in the center consol. I presume access is from the front through the center wood cover. ANy suggestions on where it is located would be appreciated. I could search through the CD but that would probably take longer thatn just going for it.

Henry

Its under the blower and accessible after the blower has been removed. It is accessible from under the hood!!

Steve I am confused by your comment that it is accesible from under the hood after the blower is removed. The manual states that it is accesible from the cabin. Take a look at the attached section from the manual. N29 is the Electronic Blower Regulator. If I need to remove the blower to get to it, then I will approach things differently.

Henry

Another mistake on the location pic on the CD...
It is as said... under the hood , under the blower.
The 3 prong feed plug on the firewall gives power to blower on pins 1 and 2, [ 1 is neg, 2 is +12v.]with low pos. trigger voltage[2-7 variable V for fan speed ] for regulator on pin 3 [center].
Verify these before going to blower/reg..
As you have the CD , just go to the wire diagram where you found N29 locator chart and click on "A/C ,104 - page1" . Scroll down to second schematic and go to locator grid M31-32 and you will see the Reg [ n29] right next to the motor .
Above both you will see the firewall plug X64 showing the firewall plug wire connector and its wire coding. [ also note fuse power ]
Notice that the regulator recieves a low voltage sig from terminal 3 to trigger the regulator. Which in turn simply allows the blower green wire to find ground through the reg. [ switched ground circuit]
The problem of diagnosing reg/motor is that you have to get to the regulator to see if it is not grounding the neg side of the blower or the blower itself is not responding to power.
Once down there, if you ground the blower ground wire and the blower energizes, the reg is faulty [ assuming you have verified the power test at the firewall SB talks about] .
Sound tricky, but if you go to the schematic, you will see how the power gets there and how the regulator acts as the ground switch..
Wish there was a better way to tell which is bad [ reg/motor] without digging down there, but there isn't ....[ to my knowledge, anyway]

Thanks for all the good advice. I will go home and look through the book manual as opposed to the CD. I was not able to find the reference that was mentioned to find the true location of the N29 relay.

Thanks for all the advice. As luck would have it, my 87 300TD has a squeeling blower motor with a good electronic blower regulator while my 95 E320 has the direct opposite problem.

Oh well, learn on one and practice on the next.

Happy ST. Patricks Day. I think I will go have some green beer.

Henry