2004 ML500 a/c is an angry wife!
#1
Junior Member
Thread Starter
2004 ML500 a/c is an angry wife!
I can’t figure out what this thing is thinking. I turn on a/c and it takes a mile of driving before it starts to cool. Other times it engages right away. On hot days here in Miami Florida it is unbearable. That’s when it takes forever to cool. Don’t tell me about heat load and time needed to cool car. No. I mean right out of the vents. It should cool somewhat within a few seconds. I am an a/c technician (not automotive) but this car killing my ego. Please shine a light for me.
#2
MBWorld Fanatic!
I can’t figure out what this thing is thinking. I turn on a/c and it takes a mile of driving before it starts to cool. Other times it engages right away. On hot days here in Miami Florida it is unbearable. That’s when it takes forever to cool. Don’t tell me about heat load and time needed to cool car. No. I mean right out of the vents. It should cool somewhat within a few seconds. I am an a/c technician (not automotive) but this car killing my ego. Please shine a light for me.
#3
Junior Member
Thread Starter
Yes I have. In regards to air-conditioning I have triple evacuated system and charged with fresh 134A. System holds a charge and does not show symptoms of leaks. My problem is finding the correct amount of refrigerant required. Throughout my searches I have come across many ranges of pressures depending on ambient temps. I’ve adjusted pressures up and down a few times. But I feel there must be a relay or something not behaving as it should and delaying compressor engagement. At some standstills the unit starts blowing warm air. I am stumped.
#4
MBWorld Fanatic!
Yes I have. In regards to air-conditioning I have triple evacuated system and charged with fresh 134A. System holds a charge and does not show symptoms of leaks. My problem is finding the correct amount of refrigerant required. Throughout my searches I have come across many ranges of pressures depending on ambient temps. I’ve adjusted pressures up and down a few times. But I feel there must be a relay or something not behaving as it should and delaying compressor engagement. At some standstills the unit starts blowing warm air. I am stumped.
I think you put too much refrigerant in the system cause the ac clutch to seize.
Run the ac system and engine and evacuate the system until you see the ac clutch engage. The car needs very low pressure otherwise damage can occur to the cooling fan and sound like a jet engine.
Any information you have gotten from people about pressures is incorrect and wrong. Disregard that info.
There should be a sticker on your car with a kg or g value for r134a. I can send an example of the one on my gl Tom. Follow it to the letter.
Last edited by kombifan; 11-01-2018 at 11:45 PM.
#5
MBWorld Fanatic!
Yes I have. In regards to air-conditioning I have triple evacuated system and charged with fresh 134A. System holds a charge and does not show symptoms of leaks. My problem is finding the correct amount of refrigerant required. Throughout my searches I have come across many ranges of pressures depending on ambient temps. I’ve adjusted pressures up and down a few times. But I feel there must be a relay or something not behaving as it should and delaying compressor engagement. At some standstills the unit starts blowing warm air. I am stumped.
There is no relay or fuse, everything is controlled by the AAC Control Module which stores all codes, which must be rear with a .
#6
Junior Member
Thread Starter
You’re right
It's obvious that you are doing this by yourself and not using a professional with the proper equipment.
There is no relay or fuse, everything is controlled by the AAC Control Module which stores all codes, which must be rear with a scanner.
#7
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This place is a joke.
It's "usually" the A/C compressor in these situations. Don't replace it with anything other than the OEM style DENSO compressor. I used a cheap Chinese compressor and the noise it makes is quite irritating, and it does take several minutes to start blowing cold even though it's new.