well, that's a whole new can of worms, nothing stock ... the 'painless' wiring kit should have some kind of wiring diagram, the factory one won't be accurate now ... on the key start solenoid the purple wire should go to the ignition switch, it feeds the coil - if you have something close to the original V8 key switch
this is the wiring - the 2nd heavy wire on the starter
should go to the alternator [or regulator if it's an externally regulated alternator], which would be why you have voltage showing at the alternator
try disconnecting the purple and see if there's a change, then disconnect the heavy wire [that likely goes to the alternator] and see what happens - could be something in the ignition or charging circuits - you also want to find out where the fuse panel gets power, most anything fused [except the light switch] should get power from the ignition switch so that everything turns off when the key is off - not sure I'd want a 70 amp fuse anyplace on the truck, there's
nothing that would blow that, but if it's in the main battery feed, then if it went you'd have no power anyplace including lights or ignition - and any individual accessory should have it's own individual fuse
Bill
