'77 tradesman 200 wiring problem
 

Hi, I have a '77 Tradesman 200 that I've had for 5 years now. About a year ago I had some electrical problems with it. The break lights, running lights, interior lights, and cigarette lighter dont work. I only have head lights, blinkers, wipers and heater. I have tore this van apart trying to to figure out the problem. No signs of wire damage anywhere. I did wire in a new fuse to replace one that was getting no power in the fuse box (thought that maybe the fuse box was bad). Of course that didn't solve the problem. I did trace the wires from the fuse that was getting no power but I didn't find any visible problems.

Could there be something other than a wire that could cause all those things to not work????? Also if someone could post a wiring diagram for this model of van I would greatly appreciate it.