air conditioner lines

Th air conditioner line that starts on top of the engine and goes and goes over the top of the engine (above the compressor) and down to the firewall leaks at the connection at the right rear of the engine. I cannot find a replacement hose or the name of this one line. this is an SVT model. It does have a electrical hookup for a switch in the line, I assume it is a shutoff of some sort for the air conditioning . Thanks for any help.