2002 Ford Escape Electrical Nightmare

I have 2002 Ford Escape 3L V6 4WD with out auto start. About 8 months ago I began to notice that when the vehicle is first started the front marker lights, dash lights, and the rear tail lights will not come on until the vehicle warms up. As I drive along the battery light goes on and off and the brake light, oil light, and the service engine light will flicker on and off. The electrical accessories will dim or die down when the battery light is on so I believe it is an actual drain and not a faulty light. So far I have changed the Multi-function switch, the battery, and checked the alternator for over charging or a drain on the battery. I have been told by others that there is a Multi-function module behind the center console that could be the problem. Since I bought the vehicle a year and a half ago the rear window defroster and wiper do not work and the heater control only works on high (I was told that this could just be a fuse in the engine compartment). All of the problems seem to be from the Firewall back to the rear of the car with the exception of the front marker lights. Please help me if it is at all possible because I am ready to have this thing melted down and sold for scrap. If you can find the problem it would save me a lot of hair pulling. Thank You. Gerry