00 ML430 - AC Problem, blowing air, but not cold *Air Condition Problem * No cold air
Thread Starter
Newbie
Joined: Dec 2005
Posts: 2
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00 ML430 - AC Problem, blowing air, but not cold *Air Condition Problem * No cold air
Hello everyone,
2000 ML430
93k miles
I'm having an AC problem similar to some others I have read on the forum. When the AC is turned on, it does blow air, but the air is NOT cold.
There are no clicking noises and the engine RPM does not increase when the AC is turned on.
With some research on the forums, I learned about the #44 30A Fuse and the low level of R134.
I found the fuse to be blown and the R134a lever to be LOW.
Replaced the blown #44 Fuse and added some R134 to the proper level, but the problem is still the same.
If any of you has any ideas that could help, i would really appreciate it.
Thanks in advance
P.S. The AC does not get much usage since it is cold most of the year, but last summer was working fine.
2000 ML430
93k miles
I'm having an AC problem similar to some others I have read on the forum. When the AC is turned on, it does blow air, but the air is NOT cold.
There are no clicking noises and the engine RPM does not increase when the AC is turned on.
With some research on the forums, I learned about the #44 30A Fuse and the low level of R134.
I found the fuse to be blown and the R134a lever to be LOW.
Replaced the blown #44 Fuse and added some R134 to the proper level, but the problem is still the same.
If any of you has any ideas that could help, i would really appreciate it.
Thanks in advance
P.S. The AC does not get much usage since it is cold most of the year, but last summer was working fine.
Senior Member
Joined: Aug 2004
Posts: 263
Likes: 11
BMW E30. I've turned to the dark side.
when your a/c compressor is turning- with the engine running. check the
8mm bolt in the very center of the front of the pulley. if it is not spinning with the pulley, your compressor has locked up. blown fuse 44's seem to eventually lead to compressor failure. they don't seem to like the 300+ psi that comes w/ no aux fan running.
8mm bolt in the very center of the front of the pulley. if it is not spinning with the pulley, your compressor has locked up. blown fuse 44's seem to eventually lead to compressor failure. they don't seem to like the 300+ psi that comes w/ no aux fan running.
Newbie
Joined: Jun 2007
Posts: 1
Likes: 0
From: LOUISVILLE, KY
2003 ml350
could be a/c switch
My a/c would not blow cold air with first use this year. Dealership charged $300 for a faulty switch. Compressor would not come on. There was enoough Freon and compressor works fine. It was only the relay.
I am not very mechanically inclined. Maybe someone else can describe what happen in better terms.
I am not very mechanically inclined. Maybe someone else can describe what happen in better terms.
Almost a Member!
Joined: Jan 2006
Posts: 71
Likes: 0
From: Chicago, IL
2001 ML430
Recharge your freon...
Hello everyone,
2000 ML430
93k miles
I'm having an AC problem similar to some others I have read on the forum. When the AC is turned on, it does blow air, but the air is NOT cold.
There are no clicking noises and the engine RPM does not increase when the AC is turned on.
With some research on the forums, I learned about the #44 30A Fuse and the low level of R134.
I found the fuse to be blown and the R134a lever to be LOW.
Replaced the blown #44 Fuse and added some R134 to the proper level, but the problem is still the same.
If any of you has any ideas that could help, i would really appreciate it.
Thanks in advance
P.S. The AC does not get much usage since it is cold most of the year, but last summer was working fine.
2000 ML430
93k miles
I'm having an AC problem similar to some others I have read on the forum. When the AC is turned on, it does blow air, but the air is NOT cold.
There are no clicking noises and the engine RPM does not increase when the AC is turned on.
With some research on the forums, I learned about the #44 30A Fuse and the low level of R134.
I found the fuse to be blown and the R134a lever to be LOW.
Replaced the blown #44 Fuse and added some R134 to the proper level, but the problem is still the same.
If any of you has any ideas that could help, i would really appreciate it.
Thanks in advance
P.S. The AC does not get much usage since it is cold most of the year, but last summer was working fine.
I thought there was something wrong with mine too...turns out there was no freon left in my AC...you can buy a recharge kit at any autostore (autozone, murrays, pepboys), plug it into the lower line, and charge it...
Look for AC recharge kits in stores....
Super Member
Joined: Nov 2001
Posts: 864
Likes: 1
ML
Hello everyone,
2000 ML430
93k miles
I'm having an AC problem similar to some others I have read on the forum. When the AC is turned on, it does blow air, but the air is NOT cold.
There are no clicking noises and the engine RPM does not increase when the AC is turned on.
With some research on the forums, I learned about the #44 30A Fuse and the low level of R134.
I found the fuse to be blown and the R134a lever to be LOW.
Replaced the blown #44 Fuse and added some R134 to the proper level, but the problem is still the same.
If any of you has any ideas that could help, i would really appreciate it.
Thanks in advance
P.S. The AC does not get much usage since it is cold most of the year, but last summer was working fine.
2000 ML430
93k miles
I'm having an AC problem similar to some others I have read on the forum. When the AC is turned on, it does blow air, but the air is NOT cold.
There are no clicking noises and the engine RPM does not increase when the AC is turned on.
With some research on the forums, I learned about the #44 30A Fuse and the low level of R134.
I found the fuse to be blown and the R134a lever to be LOW.
Replaced the blown #44 Fuse and added some R134 to the proper level, but the problem is still the same.
If any of you has any ideas that could help, i would really appreciate it.
Thanks in advance
P.S. The AC does not get much usage since it is cold most of the year, but last summer was working fine.
I hesitated responding becasue I have a 05 and the climate control system is quite different fom yours - at least the way it works. In any case, I had a similar prolem with my 05. In my case, the insides would fog up terribly on rainy days, there was barely any warm air and the cold air wasn't there at all. It was diagnosed to a faulty temperature sensor. That would require taking out the dash and I wasn't too happy. The looked further and found out that the control unit (I have no idea which one) that sends data to the temp sensor was the culprit. It was replaced and I have been having good air since March, I believe. Just my contribution.
Newbie
Joined: Jun 2007
Posts: 15
Likes: 0
My a/c isn't getting cold either. I checked that 8mm bolt and saw it wasn't turning at all. So I opened up the fuse box and replaced fuse 44 but still not getting cold or the bolt turning. Any help would be appreciated.
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Newbie
Joined: Sep 2008
Posts: 3
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2000 ml320
My A/C worked fine until i hooked up my battery wrong
I have a 2000 ml320 and last week on vacation i hooked up my new battery wrong, i know stupid mistake and also very expensive. I have changed fuse box, and abs computer. Everything works fine, drives good, great suv. Can anyone please tell me why my A/C is not turning on. The A/C problem is the only thing that i have not yet been able to fix.
Before the problem happen the A/C was blowing out very cold air!
I have changed relays, fuses, everything i am capable of doing, is there something i may have damaged?
Before the problem happen the A/C was blowing out very cold air!
I have changed relays, fuses, everything i am capable of doing, is there something i may have damaged?
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Newbie
Joined: Apr 2012
Posts: 1
Likes: 0
ML430
ADDING TOO MUCH FREON CAN RUIN COMPRESSOR
I am sure you probably already know that adding too much freon can ruin the compressor. I mistook a problem for low freon and added some to an 85 MBZ wagon we had about 20 years ago and it caused the compressor to seize up. An expensive mistake and I should have known better. It is definitely better to use gauges to determine if the system is low before adding in. Some who do AC service have a dedicated machine that vacuums all freon out of the system and then they put back the right amount so there is less chance of a tech misunderstanding the gauges.
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
If it doesn't then you are probably low on refrigerant. If it does, then wait a couple of minutes and go to the fire wall and touch both aluminum pipes, one should be cold and the other hot.
Newbie
Joined: Jul 2012
Posts: 3
Likes: 0
The first thing that must be determined is when you press the A/C button the clutch on the compressor engages, meaning itshould turn along with the pulley.
If it doesn't then you are probably low on refrigerant. If it does, then wait a couple of minutes and go to the fire wall and touch both aluminum pipes, one should be cold and the other hot.
If it doesn't then you are probably low on refrigerant. If it does, then wait a couple of minutes and go to the fire wall and touch both aluminum pipes, one should be cold and the other hot.
Super Member
Joined: Feb 2009
Posts: 780
Likes: 11
From: Dallas, TX
Range Rover
This is going to sound crazy but i had a ml430 and this is how i would solve it. Start the truck with the a/c system on. Open the hood and then let it drop and close. The shock would always kick in the clutch, and it would work for about a month and then I would have to do it again.
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Junior Member
Joined: Dec 2002
Posts: 66
Likes: 0
From: Vallejo, Ca
The first thing that must be determined is when you press the A/C button the clutch on the compressor engages, meaning itshould turn along with the pulley.
If it doesn't then you are probably low on refrigerant. If it does, then wait a couple of minutes and go to the fire wall and touch both aluminum pipes, one should be cold and the other hot.
If it doesn't then you are probably low on refrigerant. If it does, then wait a couple of minutes and go to the fire wall and touch both aluminum pipes, one should be cold and the other hot.
Newbie
Joined: Jan 2012
Posts: 11
Likes: 0
2001 ML320; 2004 E55 AMG, 2013 C250, 2010 BMW 328i
Please help... I had almost everything replaced for the A/C on my 2001 ML320: Air Door Actuator, A/C Expansion Valve O Rings, A/C Receiver Drier & O Rings, A/C Compressor & A/C Line (Comp to Cond). The A/C was working well for several months until today after I had a guy replaced the Power Steering Pump. The A/C is blowing warm air when turn on cold (the hot air is working fine). The A/C is on but the A/C Compressor is not turning on. Could this be a coincident that the A/C went out ... again? Or could the guy touch something while working on the Power Steering Pump?
Last edited by vinnienle; Mar 5, 2013 at 01:11 AM. Reason: add text
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
The only thing the P/S pump and the A/C compressor have in common is the serpentine belt.
The compressor does not operate off of a fuse or relay, but is turned on by the AAM (All Activities Module). But the AAM has nothing to do with the operation of the P/S pump.
So what you will have to do is remove both covers to the fuse/relay box. Then remove one or two additional screws and pull up the entire fuse/relay module out of the box follow steps 3-5. There is no need to disconnect the battery. Simply lay the module up side down onto a folded towel.
Then locate the X22 connector. In wire slot #9 you will find a PINK wire on one end of the connector and a BROWN/VIOLET wire on the other side.
Press the A/C button and then check both the PINK and BROWN/VIOLET wires for 12v.
The compressor does not operate off of a fuse or relay, but is turned on by the AAM (All Activities Module). But the AAM has nothing to do with the operation of the P/S pump.
So what you will have to do is remove both covers to the fuse/relay box. Then remove one or two additional screws and pull up the entire fuse/relay module out of the box follow steps 3-5. There is no need to disconnect the battery. Simply lay the module up side down onto a folded towel.
Then locate the X22 connector. In wire slot #9 you will find a PINK wire on one end of the connector and a BROWN/VIOLET wire on the other side.
Press the A/C button and then check both the PINK and BROWN/VIOLET wires for 12v.
Newbie
Joined: Jan 2012
Posts: 11
Likes: 0
2001 ML320; 2004 E55 AMG, 2013 C250, 2010 BMW 328i
The only thing the P/S pump and the A/C compressor have in common is the serpentine belt.
The compressor does not operate off of a fuse or relay, but is turned on by the AAM (All Activities Module). But the AAM has nothing to do with the operation of the P/S pump.
So what you will have to do is remove both covers to the fuse/relay box. Then remove one or two additional screws and pull up the entire fuse/relay module out of the box follow steps 3-5. There is no need to disconnect the battery. Simply lay the module up side down onto a folded towel.
Then locate the X22 connector. In wire slot #9 you will find a PINK wire on one end of the connector and a BROWN/VIOLET wire on the other side.
Press the A/C button and then check both the PINK and BROWN/VIOLET wires for 12v.
The compressor does not operate off of a fuse or relay, but is turned on by the AAM (All Activities Module). But the AAM has nothing to do with the operation of the P/S pump.
So what you will have to do is remove both covers to the fuse/relay box. Then remove one or two additional screws and pull up the entire fuse/relay module out of the box follow steps 3-5. There is no need to disconnect the battery. Simply lay the module up side down onto a folded towel.
Then locate the X22 connector. In wire slot #9 you will find a PINK wire on one end of the connector and a BROWN/VIOLET wire on the other side.
Press the A/C button and then check both the PINK and BROWN/VIOLET wires for 12v.
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Newbie
Joined: Jan 2012
Posts: 11
Likes: 0
2001 ML320; 2004 E55 AMG, 2013 C250, 2010 BMW 328i
Newbie
Joined: Jan 2012
Posts: 11
Likes: 0
2001 ML320; 2004 E55 AMG, 2013 C250, 2010 BMW 328i
Thanks again Maj. Dundee for your help.
Junior Member
Joined: May 2014
Posts: 24
Likes: 0
From: Phoeniz
2003 ML 2003
2003 ml 350 stopped blowing cold air
My 2003 ml 350 135k stopped blowing cold air . The previous day I took the car to repair shop to replace power steering fluid pump and reservoir as it was leaking pretty bad . The mechanic also replaced the radiator same day as the hose to back fill tank ..the connection broke .. Anyway right after I got my car back realized ac is no longer blowing cold air ..took it back they diagnosed some relay went dead .. And explained that was stopping the fan to work .. The system was low on freon too but no leak so they also recharged it. Question to the forum any idea which fan they were referring to and did they actually forget to power connect the fan while replacing radiator or ps pump or the relay actually went bad and it's just a coincidence ?
Last edited by Papillon; May 20, 2014 at 09:29 AM. Reason: Typo
