1999 Mercury Marquis Coolant leak

Hello,
My car has a coolant leak and I have to keep adding coolant every 200-300 miles. Recently me and my Dad replaced the alternator and noticed behind the alternator a small puddle of coolant. It appears to be possibly a heater hose but were not a 100%, with the configuration of the engine its really hard to get to where the hose and leak is. If so how do you replace it and not have to disconnect or remove major parts? If not what could be the problem? Thanks for the help.