2000 jeep grand Cherokee current to PDC but not to Junction box

You removed the transmission selector housing - you probably removed the neutral safety switch too. (hence jeep wont start). You removed the dash and components, so how can the lights/horn work at that point? My suggestion is to make sure all wiring harness connectors are re-connected and take it from there.

Thanks for answering Ken. The NSS is intact and connected and the ground wire is connected at the floor board area of the shifter. So the connection problem would still allow the ignition to go to ACC... but it won't do that. The Dash isn't removed, just some trim around the steering column and the glove box. He needs the steering column out to get the dash out to get the Heater core out. The only things disconnected on /in the dash are the Radio, Cig lighter and the AC Heater controls accessible to be removed. All ignition connectors, fuses and whatever else, have not been disconnected or removed. There's no dash board lights, dome lights, vanity lights, chimes, door lights or for that matter the hood light is off too (no current to plug).I could understand the vehicle not starting but chimes or the horn not working because the radio and cig lighter are removed? The seats I could possibly see having some cause for not starting but still no horn? I don't have feed + B to the fuse box/ junction box.but I have feed +B at connector C102

Is there a body control module disconnected in the vicinity of the seats? It does seem from your description it's from something unplugged versus an actual fault. You should still be able to turn the key to ACC & ON to straighten the wheel, even without the power steering boost (or for that matter any electrical power) Your lack of power and your ignition lock problem may be two issues. To free the ignition lock and get it to turn to ACC or ON try some of the usual fixes: grab the steering wheel and twist it slightly back and forth to unbind the ignition lock cylinder, and make certain the shifter is in park, it may have gotten bumped when you removed the housing.