AC can’t blow cool
Thread Starter
Newbie
Joined: Jun 2026
Posts: 1
Likes: 0
2013 c63
AC can’t blow cool
Hi everyone,
I recently bought my 2013 c63 and when I picked it up my AC was working perfectly.
however in the last two days I’ve noticed that my ac no longer blows cold and only blows hot/warm air at equal pressure throughout the car.
i took the car down to a mechanic and they scanned the car and found a fault for the sunlight sensor.
I replaced the sunlight sensor and had them flush and replace all of my AC gas along with testing for pressure and leaks but the problem still persists.
the mechanics say that it looks the the AC fan is spinning and the compressor clutch is engaging
however when the ac setting is set to the coldest it only delivers luke warm air or hot air if the day is hotter. Furthermore when the AC is set to the hottest setting, it increases speed and delivers the correct hot temperature.
This makes me think that there is a problem with the condenser or the ability to cool the air as it functions correctly when asked for higher temperatures
in addition both air con pipes under the bonnet have been hot with no noticeable colder line.
if anyone has thoughts or have experienced this please let me know as I’m currently stuck without cool AC in 30 degree weather, thank you!
I recently bought my 2013 c63 and when I picked it up my AC was working perfectly.
however in the last two days I’ve noticed that my ac no longer blows cold and only blows hot/warm air at equal pressure throughout the car.
i took the car down to a mechanic and they scanned the car and found a fault for the sunlight sensor.
I replaced the sunlight sensor and had them flush and replace all of my AC gas along with testing for pressure and leaks but the problem still persists.
the mechanics say that it looks the the AC fan is spinning and the compressor clutch is engaging
however when the ac setting is set to the coldest it only delivers luke warm air or hot air if the day is hotter. Furthermore when the AC is set to the hottest setting, it increases speed and delivers the correct hot temperature.
This makes me think that there is a problem with the condenser or the ability to cool the air as it functions correctly when asked for higher temperatures
in addition both air con pipes under the bonnet have been hot with no noticeable colder line.
if anyone has thoughts or have experienced this please let me know as I’m currently stuck without cool AC in 30 degree weather, thank you!
Member
Joined: Nov 2012
Posts: 232
Likes: 48
2013 C63 AMG Sedan
Hi everyone,
I recently bought my 2013 c63 and when I picked it up my AC was working perfectly.
however in the last two days I’ve noticed that my ac no longer blows cold and only blows hot/warm air at equal pressure throughout the car.
i took the car down to a mechanic and they scanned the car and found a fault for the sunlight sensor.
I replaced the sunlight sensor and had them flush and replace all of my AC gas along with testing for pressure and leaks but the problem still persists.
the mechanics say that it looks the the AC fan is spinning and the compressor clutch is engaging
however when the ac setting is set to the coldest it only delivers luke warm air or hot air if the day is hotter. Furthermore when the AC is set to the hottest setting, it increases speed and delivers the correct hot temperature.
This makes me think that there is a problem with the condenser or the ability to cool the air as it functions correctly when asked for higher temperatures
in addition both air con pipes under the bonnet have been hot with no noticeable colder line.
if anyone has thoughts or have experienced this please let me know as I’m currently stuck without cool AC in 30 degree weather, thank you!
I recently bought my 2013 c63 and when I picked it up my AC was working perfectly.
however in the last two days I’ve noticed that my ac no longer blows cold and only blows hot/warm air at equal pressure throughout the car.
i took the car down to a mechanic and they scanned the car and found a fault for the sunlight sensor.
I replaced the sunlight sensor and had them flush and replace all of my AC gas along with testing for pressure and leaks but the problem still persists.
the mechanics say that it looks the the AC fan is spinning and the compressor clutch is engaging
however when the ac setting is set to the coldest it only delivers luke warm air or hot air if the day is hotter. Furthermore when the AC is set to the hottest setting, it increases speed and delivers the correct hot temperature.
This makes me think that there is a problem with the condenser or the ability to cool the air as it functions correctly when asked for higher temperatures
in addition both air con pipes under the bonnet have been hot with no noticeable colder line.
if anyone has thoughts or have experienced this please let me know as I’m currently stuck without cool AC in 30 degree weather, thank you!
Super Member
Joined: Jun 2025
Posts: 794
Likes: 254
From: USA
Compressor clutch spinning doesn't mean it's pumping. Both lines hot = no compression happening inside.
Sunlight sensor is a red herring that only affects auto fan speed, not temperature.
You need a new compressor, plus drier and expansion valve in one go. Don't just swap the compressor alone.
If it cycles on/off every few seconds, that's low pressure same fix.
Condenser isn't your problem here.
Sunlight sensor is a red herring that only affects auto fan speed, not temperature.
You need a new compressor, plus drier and expansion valve in one go. Don't just swap the compressor alone.
If it cycles on/off every few seconds, that's low pressure same fix.
Condenser isn't your problem here.
