SilverDameon55

Hey guys,

So I have an issue with the A/C in my wife's ML350 and im not sure how to go about fixing it. I've checked the refrigerant using the A/C Pro's refill tank gauge and it's reading perfect in the green, my controls work as far as the red LED so it's not the led going. When I start the car in the morning the temp seems fine and decently cold but as I begin driving or the car starts to warm up the temp starts to warm up with it and it seems as though the drivers side is warmer than the passengers side even though both sides are set to 60. Has anyone else had an issue like this? I've checked the fuses, the compressor and everything seems to be working...I've even tried to do this little reset trick I found online where your supposed to hold the defrost button and the recirculating button at the same time for 10 seconds or until the button the start blinking...that didn't seem to work because the buttons never blinked lol. Should I attempt to remove the unit and clean it somehow or does it sound like it should be replaced?
Worst of all my screen is really starting to mess up too. One little white line that started at the bottom of the screen has turned into multiple lines and now the screen starts getting whiter and whiter till it's completely white while driving. Sometimes I can tape the screen with my finger and it comes back but with the lines. Is this a sign that its dying and needs replaced? Where can I find one for a decent price?
thanks

CLK Group

Had a similar A/C situation with our C350. Code pointed to the Blower Motor. Found that a TSB had been issued for an updated Regulator. Had the Blower Regulator replaced and issue was fixed.

SilverDameon55

Thank you for the response but I attempted to Google that part and I dont see that the 09 ml350 had one...unless I just can't locate it. Do you have a part number or know how to go abouts locating it?

Maj. Dundee

Please UPDATE YOUR PROFILE in USER CP to include the year and model. Then in a separate post list your full vin#. This will indicate your code for AC.

CLK Group

@silverdameon55 - the blower motor regulator in my 2008 ML320 is not available separately and is probably the case for the 2009.

See my fix here: https://www.benzworld.org/forums/w16...rol-issue.html

SilverDameon55

is there a way I can do this on the mobile version? I dont have a computer and dont see the User CP part..

CLK thank you for the link, the video helped show that's its not that hard to remove the blower and check the resistor that's connected to it. The only difference is that my air still blows and the heater works perfect. My issue is that the A/C is only cold when starting the car but as I drive, the temp of the air gets warmer till it feels as though the A/C is set to 70 or something. I think I may still pull the blower put and at least check the circuit board though and report back.

Maj. Dundee

And what about your vin#?

Maj. Dundee

The blower motor is not the problem here. I believe it is the Stepper Motor on the driver's side that is faulty.

The only way to find out is to read the codes in the AAC Control Module with a .

SilverDameon55

Stepper Motor? Not sure I've ever heard of something like that. The VIN is 4JGBB56E49A528100

SilverDameon55

You dont think it may be the temperature sensor found in the pipe next to the blower motor under the dash? Something like that was my first thought.

cb09ml350

2009 ML with 91k miles.

Code 9006 or 9007 code on intermittent ac. with StarD
It works on and off.
No rhyme or reason.

Is this a pressure switch issue.

Thanks

SilverDameon55

Are you asking me or is this your personal ML?

SilverDameon55

Here is my blower motor resistor. Looks ok to me.

CLK Group

@silverdameon55 - absent any visible corrosion I would have an Indy MB shop check for any codes. If none, then have them check the stepper motors. If those are found to be OK have them reset the system with Star Diagnostic.

If issue persists, then replacing the Climate Control Unit would be next step. Mercedes wants $1,200 just for the part. I found a used one from another 2008 on eBay for $200 which includes a one year warranty from Square Trade. You can replace it yourself via a YouTube video like I did.

SilverDameon55

@CLK, yeah I'm going to have to get it scanned I guess and see what it says. What I've done so far is remove the 2 temperature sensors from the plastic pipes under the dash and took some alchohol on a Qtip and cleaned them. I also noticed the stepper motor on the driver's side and it appears to be working just fine. I've clicked the directional flow from foot to head a few times and watched it move with no issues nor clicking as some have reported. I think it has to be the climate controls or something like that.

texterted

There looks to be some leakage going on, on that capacitor bottom right, of the picture you posted.

SilverDameon55

Yes after you said that I looked back and do see it myself. Does it appear enough to possibly be an issue or possibly the cause of my problem?

Maj. Dundee

There are 8 stepper/actuator motors. Only reading the codes (9xxx) in the AAC control Module will tell you.

texterted

1st thing I'd do though, is to get the A/C contents checked on some proper gauges. Those home kits are notoriously unreliable.

Maj. Dundee

Tex, he only has a cooling problem with the driver's side.

texterted

Aye, I've heard of it do that before, with a low charge.

Besides, I cover the basics before pulling the car to bits!

Maj. Dundee

I never made any suggestion to pull the car to bits.

texterted

I never said you did but it looks like he has been already.

SilverDameon55

@Maj & Tex: yes my issues originally started on the drivers side with the temp being a bit warmer than the passengers side. Now though it seems as though everything is warming up as the car is in motion. I'm going to be stoping by my mechanic tomorrow to see if he can scan it and then report back the results. He specializes in euro cars so he has the correct scanner. Onces that's done I'll have a better idea as to my direction. I just hope it's not going to break the bank!

texterted

Seriously, get some proper gauges hooked up and check the charge level first.