Originally Posted by otter440
i am doing 1970 challenger went with all new wiring in the car i have pretty much evrything working but the dash lights and headlamps. i have tried different h/l switches. dash dimmer switch, and floor dimmer switch. for some reason i have no power to the orange wires in the dash and no headlamps. the marker lights,taillights and parklamps all work fuse is good. I am baffled any suggestions thanks


While the diagram that EW1BH27 posted is helpful, you really need the schematic for the entire car or at least those showing the dashboard/dimmer switch forward. You can try to get by with out it but it really saves time>
the entire service manual is available here for FREE FREE Manuals
I print out the sections needed, tape them together if necessary, and strongly encourage a box of assorted colored pencils to trace the wires.
I would go after each circuit separately Starting with the headlights. It may take a little bit to familiarize yourself with the way the schematic(s) were done but it is pretty easy. Optionally buy one of the laminated full size color coded schematics.

1. Do you have power at the center terminal of the dimmer switch? that power comes from the headlight switch. No power? check the other two terminals just for giggles. I've seen several mis-wires on "NEW" harnesses as well as bad crimps.
a). Check the headlight switch to verify power is present at the terminal that feeds the H/L's when they are on. Be aware some cars use separate 12v feeds for the H/L's and other lights. the largest wire is normally headlights.
b) If you don't have power at the output to the dimmer, using a wiring diagram for YOUR car work your way back to find the source of that power. If there are connectors along the way, checking each connector and the in and out terminals.

keep us posted beer