lacotorra28

I am posting for my neighbor who has a shop and is having trouble trying to track down why the a/c compressor will not run. He ran a wire from the compressor directly to the positive battery terminal to test the compressor which makes it operate. It blows cold air but he can't leave the line since it would burn up the compressor of course. He did have to put two and a half small cans of coolant in the system. I searched everywhere and I have not seen this problem on any other thread. If I missed one please forgive me. I can delete this thread if it is a repeat or link to redirect. Since he is getting more mercedes in his shop I imagine he is going to be a long time member, hehehe.
email lacotorra28@hotmail.com
Thank You

C230 Sport Coup

Did you check the fuses?

lacotorra28

Yes unless there is a fuse in an odd location?

samaritrey

Has the pressure been checked after adding the cans? If the system detects that the pressure is to low it won't turn on the compressor. If that checks out then the pressure sensor could also be bad and hooking the car up to Star would be a very good idea.

Glyn M Ruck

+1^ Check system pressure. There is a pressure/temp sensor in the front condenser below the radiator. If refrigerant pressure is low the A/C won't work to protect the compressor.

lacotorra28

After filling completely it still only worked with the bypass even though the pressure was correct. The way he finally fixed it was by replacing the complete dash control panel in the center console from another car of the same model and year. This fixed the problem on one car but now the same issue is in the other car. What in that control panel specificly would cause the A/C to not work unless bypassed by a wire to the battery? One other issue with both cars are the wipers. They are not working at all and the basic stuff like fuses have been checked. I know he likes these cars but wow do they have issues.
A side note out of curiousity. Why would Mercedes Benz make such lemons like these since I see everyone online complaining about these models. Thanks
Are there any websites where you can pay a fee for unlimited access to diagrams for not just these models but other manufactures online so he can download anything going forward??

Thanks

VVF

When I was researching about which car to buy, I wanted to ride a bicycle instead. Every make and every model from every year is a total and complete POS according to the internets.
So you fixed it by replacing the control thingie. How about replacing the whole AC system in Fords due to black death?

samaritrey

Yeah every car model ever made can be the worst car ever made or the Best car ever. My W203 is probably one of the best out there with over 200,000 miles and very few issues (knocking on wood) while others on here have endless issues.

Glyn M Ruck

The real problem here is that faults are supposed to be diagnosed with the help of a Star. We help people here from experience & virtually blind to save them money but are not always going to get it correct. 99% of the time an inoperative HVAC compressor is due to low system pressure. The other 1% could be many things from the main system controller to a sniffer sensor blown.

The dealer also has the pleasure of being able to throw parts at the problem & if they don't work return them to stock or charge an unsuspecting customer for something they don't need.

Diagnosis by remote control is only as good as experience & the quality of information given.