Chrysler Repair: 2002 Chrysler T&C AC, black caps, highside

Question
Which port is used to add freon to the system?  There is one up close to the fan, and one back near the firewall.  Both have black caps on them.  I thought the highside was to have a blue cap, so I am confused. Thanks for your help

Answer
the 2 ports are different size  the kits u get in the store are for low side only  if i remember right the one on the back is the low side. But any way  u wont be able to get the smaller low side connector onto the high side. If u are adding freon then I take it u have a leak huh?I live in Atlanta and I can look at it for u.