Where do I find the low pressure ac port

.click image. This is Explorer specific.

If the A/C is working at all, if the line is cold it's wrong. That's the high side

I think you got that backwards FordNut, high side line is the hot line, small diameter is high large diameter is low.

DOH! Of course. The high side is compressed and not expanded yet to get cold. Thanks for the correction. I remember before they made it idiot proof (or resistant) and the two ports were the same size, and you could still buy R12 Freon people were hooking the can of Freon to the high side and pumping in to the can and blowing themselves up when the can exploded.