sl500 a/c problem

[wspanic]

I have a 2003 sl500 that i recently purchased, the a/c off light is stuck on and my mb dealer is 100 miles away. I've seen some diagnostic procedured listed for the eclass but mine does not have a display on the a/c controls, I,ve checked the freon presures and the appear to be correct. I also found the coolin fan fuse under the hood had blown and replaced it. Is there another fuse box inside the car? I did not get an owners maual with the car. any help would greatly be appreciated, thanks

[bobterry99]

Your problem is probably the evaporator temperature sensor. It can be a problem with the sensor itself or an incorrect parameter set in the climate control module. If no work has been done to the climate control, I would suppose the parameter is not the problem, and I would focus on the sensor. But if the problem is an incorrect parameter, then you will have to take the car to a dealer or an independent that has Mercedes' SDS software.

The easiest way for you to troubleshoot the sensor would be to invest in a Carsoft scanner from eBay. This would cost about $250.

Another way to troubleshoot would be to connect an electronic multimeter to the sensor and measure its resistance. At a temperature of 45 degrees Celsius the resistance should be 9K ohms; at 0 degrees Celsius it should be 1.2K ohm.

You may want to just order a new sensor. The part number is 220 830 07 72. It sells for $45 at Parts.com - For every part of your life and is quick and easy to install.