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More '70 Charger headlight relay weirdness

JerseyJoe

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I've recently installed the plug and play relay harness, and I'm having issues similar to Kern Dog's. After hunting around with wiring diagram in hand, it's working properly with the high beams selected BUT the brake warning light on the dash just barely glows...

In low beam the headlight doors open and the low beams turn on with the ignition key turned on. No brake warning light glow. The lights go out only when the key is off but the doors stay open. The headlight switch does nothing to the low beams.

I have used a Bosch relay on the headlight motor wiring for years with no problem, I tried several relays in its place including the new ones from the new harness with no changes.
All fuses are out of the car (except the new headlight relay harness and concealed motor circuit) and the electric fuel pump, MSD, and aftermarket A/C power is removed right now.

I'm leaning toward the footswitch for the beam selector unless someone has some input. The footswitch is about 5 years old, NAPA brand, and the connector was new and is not melted.
The brake warning light could possibly be a separate issue as well.
Just asking in case I'm looking in the wrong direction.
 
UGH. I figured it out. I think typing out the problem made it click.
The headlight motor bosch relay was grounded to the brake warning light ground wire. That made the headlight door operation goofy. The door relay wiring is isolated from the brake warning light wiring, wired like the diagram the KD's thread. It all works now.
 
Glad you figured it out.

That's another thing, like EFI computers and dirty input voltages with noise that will cause issues. Clean ground in the files for future folks.
 
Glad you figured it out.
Thanks for your help. Once I got it to the point the lights worked but the doors didn’t, I figured it was sloppy wiring making the motor not know which way to turn.
 
I didn't figure out the problem myself. I had help.
I did the Bosch relay to both of my cars. Both are grounded to the dash frame.
 
You’re thread was a big help. Man I hate staring at wiring waiting for it to make sense.
 
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