2003 sl500 ac problem - PeachParts Mercedes-Benz Forum

khanvinced · #1 04-14-2007, 12:29 AM

i have a 2003 sl500. just ran to a problem with the ac. the ac off button is on all the time. when u hit it to turn on the compressor ( i assume), it just blinks twice and then stays on solid again. it was working fine the day before blowing cold air like usual. don't know if any of the following is related but i want to be thorough and waste too much of your time. it was raining that day when the ac stop working. just the day before the ac stop working properly, esp, bas, abs malfunction occured but went away on its own. don't know how or why. just happened on it's own.

second problem. don't know why but the vents blow a very foul smell. carpets are perfectly clean. nothing in or under the seats. coming from just the vents. same smell with hear or ac. doesn't matter if it si recirculating air or fresh air. is there a filter i can change? do i have water pooling somewhere? drainage issue?

thirdly, top starting to loosen. more rattles and starting to come about. what can i do?

mostly importantly, thank you to you guys who take the time to help guys like me. y'all help me with the 94 500 sl. hopefully u can do the same here.

stevebfl · #2 04-14-2007, 10:58 AM

Unfortunately you will probably need to view fault codes on the AC. Possibly a review of actual values could help. The 220 car does show actual values in the display but I'm not sure whether the 230 car does. I'd suspect a problem with the pressure sensor, evap or ambient temp sensors. Unfortunately the networking on that car means that the sensor interpretation doesn't happen at the AC control panel necessarily, which means a bad reading doesn't necessarily mean a sensor problem.

khanvinced · #3 04-14-2007, 05:16 PM

is there any way to get an exact diagnoses?

stevebfl · #4 04-14-2007, 05:23 PM

The answer is likely simple for a professional with proper training using the proper diagnostic computer. As the cars get more complicated crystall balls and parts store diagnostics really can't work. Too many parts, too many relationships.

I had a Mini this last week that had a non functioning compressor. Ambient temp showed -10 C the controller of course figured no need for AC. We tested the sensor it was reading properly. Turned out that the sensor reports to the general module and it was defective. Just not a very easy situation to throw parts at and it was just a Mini!