Where's my electrical gremlins? Wont start!

What "we" are working on here (I say "we" because YOU all are the ones giving me the much appreciated advice :notworth: !) is a '77 ramcharger w/a modestly modified '70 440. A Father - Son project that we did from '07 to '09. He's been driving it since high school, now college. Back then, we bought 2 new underhood harnesses: motor & lights . Inside has the new bulkhead connector, fuse box, ignition & turnsignal. So all new wiring in it except for the rear. In other words: we touched everything so I'm not about to discount any advice on solving this. FABO has the most knowledgable electrical gurus. These problems have been surfacing and he's been throwing new cables and solonoids and etc. at it since. I'm stumped.