Hey everyone, so my climate control stopped blowing air one day a few weeks ago. I don't drive the car often in winter but do take it out every so often. One day after filling gas all of a sudden the blower started working again but the speeds were all wonky; turning it to the lowest would put the blower on full blast etc. Additionally, when I shut the car off, the blower still kept going so ended up removing the 30A Fuse 25 in the engine bay.

After reading a bunch of forums on here I decided to swap out the resistor as suggested by many people (purchased from Rock Auto). I replaced it successfully, installed the fuse but started the car and still no air from the blower. Is there some sort of Climate Control Reset that I need to do or can it possibly be the blower motor itself.

P.S The head of one of the screws in the blower motor broke so it will be a PITA to remove the entire unit.

 

Here are all of the master reset procedures that I'm currently aware of (including the HVAC):

Preparation Steps:
1. Make sure your steering wheel is straight.
2. Make sure your windows are all the way up
3. Make sure your sun roof is completely closed (if you have one)
4. Make sure your parking brake is released.
6. Turn off your stereo and make sure you have your stereo's Anti-theft code.
7. Turn off your heat/AC blower
8. Turn off your lights
9. Make sure your doors are UNLOCKED.

Now, disconnect battery 30 secs and then reconnect.
Get in car close the door and turn the key to position 2 (Just before you start the engine but do not start it)

1. Resetting your windows: Bring down both windows at the same time by holding the switches just before the click that brings them down automatically.
Once both windows are all the way down make both switches click by pressing them all the way down and hold them for 3 secs
- (This lets the ECU learn that that is the end of the window track and it records it in memory).
- Do the same for closing the windows by holding both switches and making them click once the windows are all the way up.
2. Turn on your blower and make both sides go to 72 degrees (if you have this type of heater control) by pressing both up and down buttons at the same time.
- This will calibrate the ECU
3. Turn on your stereo and enter you stereo code.
4. Pull the sun roof all the way back and all the way forward then up and then done.

6. Turn all of you lights on and back off, including your fog lights.

7. Turn the key back to position 0.

8. Turn on your engine. You will get 2 malfunctions, your ABS and ESP lights will be on and must be calibrated.

9. Calibrate your ABS and ESP systems by turning the steering wheel all the way to your RIGHT and then all the way to your LEFT,
then bring it back to center. Notice the two yellow lights disappear from you dashboard.

10. Let your car run in idle for about 5 minutes and then take it for a spin.
- Remember your ECU is still getting all the readings from all the sensors on your car so drive slowly first then faster... and so on..
- you're basically teaching your ECU how to handle your car.


Throttle Reset

1. Get in and shut the door
2. Turn key to position 2 (just before you start the engine).
3. Press the gas pedal to the floor... past the kick down point...
4. Hold the pedal there for 15 seconds
5. After 15 seconds while foot still planted, turn the key off but do not remove it.
6. Release gas pedal and wait 3 mins. Do nothing, you should here a click near key at 3 mins.
7. After the 3 minutes start the car and drive off normally... you should notice a difference in the shift pattern and smoothness.


Service Reset
Turn the car on to the 2nd key position, all the way ON, but do not start it.

- Then scroll through and find the A/B Service notification. Hold the "R" or reset button on the dash.
After a few seconds a message will display on screen asking you if you would like to reset the service notification.
Once this happens let off of the "R" button.
- Press and hold the "R" button one more time until the reset is complete.

Valve Reset:
1. move valve with finger off 90 degrees, turn key to 2nd position, let valve close and open, wait for "click",
turn off key, turn back on for 45 secs during which time the valve will close and open again, key off (Not been able to make this work).

Trunk Release:
1. Remove drivers fuse panel, pull 4 fuses on left 7.5A and 5A, wait few secs and replace,
- then try door unlock switch to see if it works, this will tell you if alarm is deactivated.
- if not try other fuses. Passenger Mirror auto-dip reset:1- Turn key to position 2

Side View mirror dip:
1. Select reverse, adjust mirror down so you can see curb for reversing etc.
- press Green store button on drivers door control next to the seat adjustment for a couple of seconds,
- then within 3 secs press the mirror control again - just once - in any direction, mirror is now stored.
- return to Gear shift to Park.
- wait 17 secs - mirror will return to normal position.
- Select reverse and test to make sure it dips.
- DONE.

Good Luck!

 

Hello Mitra

Issues with the W208/A208 HVAC system can easily be identified and repaired, using it's N22 dashboard push button controller, which has complete builtin self test diagnostic capabilities.

There are 3 different diagnostic test, you can run to see your HVAC system's:

-Current actual values, of numerous system parameters
-Any stored diagnostic trouble codes, which must be erased after a faulty component is replaced
-An individual flap test to verify that the vacuum actuated vent flaps are opening and/or closing correctly

As numerous forum posts identified, the blower control voltage regulator has been a ubiquitous problem for the vast number of either no or erratic operation of the blower motor.

While it's an easy DIY repair replacement part repair, there are numerous knock off parts available, that are dead on arrival and/or soon fail, so it's important to only use a genuine MB (OE) or from the company (OEM) that manufactures the part for MB.

The purpose of the voltage regulator is to supply a varying voltage to the motor, where at minimum fan speed the voltage is 0.8 volts and at maximum fan speed 6.0 volts.

You can verify that the part you installed is working properly with a multimeter, where the voltage on regulator's input terminal is at or near the vehicle battery voltage and the voltage on regulator's output terminal is between 0.8 and 6.0 volts.

Alternatively, you can run the diagnostic system value test setup and current system parameter values as described below.

Note: The reading in step 10 will show the your blower control voltage





Lastly, when replacing a faulty voltage regulator, there is no climate control reset necessary.

If the voltage supplied to the blower are within the nominal operating range and blower motor does not operate, it could be worn motor brushes or the motor itself.

 

Thanks alot for this in-depth breakdown. Looks like I have some stuff to keep me busy. I called MB in my area for the price on the OEM part from them and it's like $550 CAD lolol

 

The $550 CAD price includes diagnostics and installation at the prevailing dealership shop rates, the replacement part and profit.

Use the procedure I provided to determine if your blower regulator is working properly (e.g. should only take you 5 minutes).

If it's the culprit, a replacement OEM regulator is only $51.29 US and is an easy DIY replacement .

https://www.autohausaz.com/catalog/c...tor?s=d&page=1

 

So I ran the test as you outlined and the voltage reports as correct in the range specified of 0.8 - 6V. Is it safe to assume then the Blower motor itself is the culprit? I'm not sure if it's worth it to try to acquire the brushes or just purchase the motor outright.

 

While your blower motor or worn brushes may likely be the culprit, there are some additional diagnostic/troubleshooting measures that should be explored (e.g. the system values for the B10/4 in-car temperature sensor, the B14 outside temperature sensor, the terminal 58d percent battery voltage).

That said, when other electrical motors, such as the engine's starter motor, alternator, one of the 3 power seat motors fail to operate, it's usually the brushes (e.g. lack of spring tension and/or worn down carbon blocks), which often come back to life after a few taps with a rubber hammer, 2x4 etc..

My suggestion would be watch the below video, which will show how to determine if your blower motor issue is only worn brushes, as well as a temporary fix.

 

Hey, just an update. I looked at the video and followed the steps. The blower would start to spin just a bit and then grind to a halt. I was able to remove the blower motor and found that it is VERY stiff to turn. I'm not 100% sure but I suspect it should move more freely. I'm guessing I have to go ahead and buy a new blower motor?

 

The other issue is all the screws have a significant amount of deterioration and should be replaced. Where would I find these?

 

Just a final update to this, I swapped out the blower motor now all is well and have heat in the car! For the next person that needs to change the four screws used for mounting the blower motor, the part number is A1409841629

It cost me $4 CAD / screw at the stealership .........

 

good job!! I was going to say to tap the motor a few times..one squirt spray wd40...mine had same issue...once it got going, have not had problem since

 

Thanks alot! I did try tapping a few times but didn't try WD-40 for some reason. I still have the old motor so maybe I'll try to revive it. It's so nice having heat once again