Water Dripping from Air Conditioner | Condensation Drain Pipe

Water Dripping from Air Conditioner - We have 2 air conditioning units in our house and 2 pipes protrude from the roof. One of the pipes is dripping water. We were told to look for a blockage and to empty the pans. I don’t see where to check for a blockage. Any suggestions?
The air conditioning units we have: Bryant models 373LAV, 376CAV Downflow/Horizontal and 383KAV, 395CAV Upflow Gas Furnace. (more…)