88 cougar will not hold a charge
 

Stumped by this one. I have replaced battery, starter, checked alternator, fuses and starter relay. seems to have some sort of drain on battery but cannot find it. have unplugged just about everything and still no change it will drain a new battery in two days. help please any advice or suggestions to point me in other directions would help.
Does anyone know where the relay box is for this vehicle? i.e. fuel pump etc. i want to try those but i cannot find them

ring out the wires (ohm out, continuity check, etc) between the alternator and the battery. if those are broken, even a good alternator will not charge the battery. also, check the lights in the trunk and hood and make sure they are actually turning off when you shut them. If not, that may be your drain and the switched bulb socket (usually a mercury - as in the liquid metal, not the car company - switch) needs to be replaced.