Installed a new Painless Wiring Harness this weekend on my son's 70 4x4,followed instructions and went pretty smooth.tested circuits everthing looked ok,,,turned lights on,had headlights ,high/low (installed relays),turn signals,marker lights .brake lights . Started truck ran great ,dash lights and gauges all worked great. Turned ignition swith off and nothing happened???truck still ran fine,,,,pulled both wires off battery post still ran great,,,had to pull plug out of the alternator to stop the truck!..Again i have goofed up!
ANY Ideas?????

Here you go.

http://67-72chevytrucks.com/vboard/showthread.php?t=186065&highlight=painless

installed the diode from radio shack and fixed the problem,,,