I'm trying to get my a/c system working on my 1.9 Vanagon, using a conversion kit from Interdynamics. (I'd also like to try the same on my 2.1 eventually) My trouble is that the compressor seems to have two low-side connections a few inches out on the lines. I've compared this to my 2.1, which has one low-side fitting a few inches out on the line. I thought that I should have one low-side fitting near the compressor, and a high-side connection somewhere near the evaporator. 

One line says SUC (I'm assuming for suction) and one says DIS (I'm assuming for discharge) Does this mean that someone has installed the wrong fitting on one of the lines? Which side (suction or discharge) should the low-side (the one I'm adding the refrigerant to) be on?

Thanks,
Ed in CT