erh245

I have a AC issue with my SLK 99 230. I believe it is a R170. The compressor runs but I do not have cold air. The high pressure line coming from the compressor is hot and it is hot all the way to the firewall. The low pressure line is warm - about the engine compartment temp. My question is - What system does MB use at the evaporator to control the cooling? My AC experience is from back in the 70's and 80's.
Any suggestions or suspisions about the problem?

Earl