can some please help me out i put a new battery in thinking that was the problem because my battery light came on i put a new battery in still the light was on so i put a new altenator in tested it when i bought it said it was good i put in in my truck still battery light stays on and battery was loosing volts any idea what it could be its a 2001 5.4 super duty

 

Check all wires going to the Alt. Check all fuse links. Alt may not be getting power to main wire.