where you have the blue line to is the high press side it pumps from the compresser to the condenser raising the press here makes the cond hot then it cools in the cond .where you have the yellow is the low side that is where i charged it from i never used the port where you have the red line
Your Factory Service Manual will show you what you need to know . Don't have one ? Service Manuals – MyMopar
Do you have a vacuum pump ? A strong fan in front of the condenser ? Vent thermometer ? Pressure chart for the different ambient temperatures ? And you are going to recharge with R12, right ? Proper oil if it is an empty new/rebuilt compressor ?
Red hose goes to the hi side, which is the smaller line. Blue hose goes to the low side which is the larger line. The yellow hose hooks to the vacuum pump, or the freon tank.