If you check mymopar you can see the triple T in the '70 challenger "A" wiring diagram which is what I was going by. OK it starts/runs but the voltage is all over the place? I'm at a loss so far as to why the voltage is not reasonably steady but an intermittent connection is what is jumping out at me but I know I'm missing something EDIT I think I'd jump the MSD directly from the batt positive and negative posts to try & pin down if the prob is in the MSD box or in the wiring, we gotta get some progress going