Last year I had the a/c retro fitted to the new 134a stuff along with a new compressor. It gets comfortable after about 15 minutes of highway driving but not like it was after I had it redone. I went and bought a kit to recharge the unit with the dial gauge, etc. But I can't seem to locate the low pressure fitting. I see a grey cap to the back of the compressor, but not where the line that goes into the evaporator behind the dash per the instructions. I can see where the fat hose coming off the compressor goes into the firewall and the other one coming off the drier goes into the firewall also, but no low pressure port. How do I find it? Help it's hot here in Florida........

Thanks