The friend who tried to help with the wiring made this post on another site. It has more information in it, so I figured it would help you guys in helping me:
i'm working on a friends 79 el camino that has had the monte carlo front end installed on it, so it has gone from single headlights to the dual. whoever did the wiring really sucked at it (wires with multiple butt connectors, shoddy grounds, etc) so today i ripped it all out and completely rewired the headlights according to the 84 monte carlo diagram,the only difference between the two is that the additional high beams are simply spliced into the high side on the high/low beams
problem is that the high beams (the inside lights) glow dimly when the low beams are on
All of the grounds are good, and I changed the wiring slightly so that the high/low beams have their own ground. I did check the dimmer switch, and its not feeding additional power out through the high beam side.
the high beams only stop glowing when both of the high/low beams are unplugged.
You guys have any advice?