Jiggle shifter makes lights blink?, horn not working?, loose bearings in column?,..... points to upper column area. Turn signal switch bad, something pinching wire, loose connection, faulty connector. Wire connection being torqued when turning or shifting. This is an intermittent/loose connection/wire pinch, not a short.....YET! Examine any hot wire going into column, probably to turn sig switch. Examine all connections at turn signal switch and it's connector. Almost EVERYTHING runs thru the turn signal switch. Observe operation of shift lever vs. wiring. Also see if anything moves in there that should not or is moving/stressing a wire: when shifting trans lever, turn signal lever, turning steering wheel, tilting steering wheel. Check neutral safety switch hook up. It is probably some connection you did not touch when rewiring.
The horn operates by grounding a ground wire from the horn trumpet. I don't think it should spark. Horn honking when turning is obviously bad. You may have two problems at once or they may be related.
BIG QUESTION, take your time here:
Did this happen out of the blue? Been working fine until one day? Did it happen after you or someone did some electrical wiring or replace a component? Was there an "event" of any kind just before? Did you just buy this truck? How long has it been "blinking" things?
Generally speaking: Integrated circuits, printed wiring board assemblies and that family are electronics. Most of our older trucks are electrical. Your radio, if transistor, or an HEI could be called electronic. Our trucks don't manipulate electrons. They just hook up a bunch of mechanical switches to operate motors, bulbs, coils (lighter, gauges, other) a few discrete components (radio, other) and an electromagnet or two.
The 65 may have a printed circuit board or a flex print to connect dash components together, still not "electronic".
