I need to do this to my beater, which one do I plug the hose into, the low port or the high port? TIA

 

I alwas add to the low side.

 

Add to the low side. If its R134a it will only hook up to the low side if you are using one of the megaautopart kits.

 

Yep low side and its made for anyone can use it, so it will only hook to the low side.

 

You can only hook it up one way (the low side). If your using a DIY kit make sure the clutch is engaging or it will not take unless you jump the low pressure switch with a paper clip or somthing. You have a leak if its low I suggest adding dye if you dont have a sniffer to diag and fix the problem.