A/C suddenly warm
Thread Starter
Newbie
Joined: Mar 2023
Posts: 10
Likes: 0
From: Ontario, Canada
2007 Mercedes C280 W203
A/C suddenly warm
Hey all,
Recently the A/C in my 2007 c280 has been blowing warm air. No unusual noises just warm air all of a sudden and it hasn't been cold since. I have done some quick diagnosis and scanned the codes and got a P0128 code for a faulty thermostat. I know my thermostat has been needing to be replaced but I have read online that the car checks how long the engine takes to reach temperature, and due to the faulty thermostat if it takes too long it locks out the A/C to protect the engine. I was wondering if anyone can confirm or deny this.
So far with the A/C set to the coldest and the fan set to max both refrigerant lines are warm. I have verified that the system has sufficient pressure so I know it isn't a gas leak so this is showing that the compressor is dead or not running to my understanding.
For now I'm going to try replacing the thermostat and leaving the battery unplugged to clear any residual lockouts but am open to hearing if anyone has experienced this before or knows if this is even true.
Thanks
Anthony
Recently the A/C in my 2007 c280 has been blowing warm air. No unusual noises just warm air all of a sudden and it hasn't been cold since. I have done some quick diagnosis and scanned the codes and got a P0128 code for a faulty thermostat. I know my thermostat has been needing to be replaced but I have read online that the car checks how long the engine takes to reach temperature, and due to the faulty thermostat if it takes too long it locks out the A/C to protect the engine. I was wondering if anyone can confirm or deny this.
So far with the A/C set to the coldest and the fan set to max both refrigerant lines are warm. I have verified that the system has sufficient pressure so I know it isn't a gas leak so this is showing that the compressor is dead or not running to my understanding.
For now I'm going to try replacing the thermostat and leaving the battery unplugged to clear any residual lockouts but am open to hearing if anyone has experienced this before or knows if this is even true.
Thanks
Anthony
Thread Starter
Newbie
Joined: Mar 2023
Posts: 10
Likes: 0
From: Ontario, Canada
2007 Mercedes C280 W203
I kind of figured that; seemed weird that just now the A/C goes out knowing that the thermostat was bad for a while. I already checked the fuses and nothing was blown for the compressor. My scan tool is basic so I can't see if the compressor is being called on and I don't want to just assume that it's dead.
Any tips for diagnosing the compressor?
Any tips for diagnosing the compressor?
Senior Member
Joined: Mar 2023
Posts: 361
Likes: 108
C230K
The simplest method would probably involve a scan tool that activates the compressor. Otherwise you'll have to trace the wires, check them for any open or short circuits, and try to jumpstart the compressor with external 12v and ground.
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
