Hi,
I recently had trouble starting my 96 F150. I had interior lights by starter wouldn't turn over. This has normally been the result of a lose ground battery terminal. I bought new terminals but before I put them on the truck started and I drove home. Then same problem so I replaced the terminals and as I was connecting the ground I had no power. The alarm didn't go off and I lost all interior power. I replaced the solenoid and have power from the battery side. I also tested and have power at the starter. I have no power to the ignition side of the solenoid and no horn headlights or domelights. How do I test to see if power is coming into the main power distribution panel in the engine

 

Well, the starter mounted solenoid receives power from the battery side of the fender mounted solenoid, so you have power to there. With the key on see if first constant 12v is triggering the fender mounted solenoid, then see if 12v is making it through the solenoid then onward to the power distribution box.

Also verify that the ground wire isn't corroded at the mid cable frame connection.

Adrianspeeder