My headlight relay install caused some really strange results

[Kern Dog]

Since I am currently rewiring stuff under the dash, I am looking back at the headlight relay attempt I tried in April 2013.
The car is a 1970 Charger. I had a guy helping me with the wiring. He has a 71 Road Runner that he has owned since it was new. He had installed relays and did the Ammeter bypass years ago and offered to help.
The battery is in the trunk in my car, opening up a convenient place to mount the relay box where the battery used to be. Bob said only the low beams needed relays so he tapped into the low beam circuit between the master cylinder and core support. After the "upgrade", the lights came on fine but would not go off by the switch UNLESS I switched on the high beams. Huh?? One time when I tried to shut off the lights by the switch and the doors would not close either....UNTIL I stepped on the dimmer switch.
I ended up ordering a new headlight harness. The headlights were brighter and all of the strange habits stopped. Lately I've been curious as to what we did wrong. Did we splice into the wrong wire or at the wrong place? Bobs car showed none of the same problems that I had but the Road Runner does not have headlight doors. The headlight door relay is clearly visible with the guage cluster out.  I'd really appreciate anyones input on what I did wrong as well as the correct way to install these relays!
Thanks, Greg

[Dino]

I replied in your other thread before I saw this.

So somehow the power to operate the headlight doors was linked with the power source for the highbeams.  That's messed up!!  I'm unsure what went wrong but as long as it's been remedied I wouldn't worry about it too much.  You can tudy the wiring schematics and trace the origins of power recreating the steps you had to take to shut off the low beams and close the doors.

Since you have the battery in the trunk I'd run the power feed for the relays either off the starter relay or straight off the alternator.  Use a fuse or circuit breaker between that power wire and the relays.  Where all this is mounted does not matter.  You decide where it looks good and is easily reached in case you need to replace a relay or a fuse.  I'd use a relay each for low and high beams and a fuse each.  I opted for a self resetting circuit breaker instead.  As long as the install is done well, there's very little that can go wrong here so it's just for backup.  The circuit breaker wll remain off until the power levels are back to normal.  I like having them on the rad support.  With the battery installed you can barely see them and I can still get to them easily.  Since your battery is in the trunk, do you have anything in its place in the stock location?

[Kern Dog]

Back in 2013 when we were working on the engine side wiring, Bob did only the low beams. After I saw that they acted weird, I tried connecting the wiring back without relays and they worked as normal. It was because of this that I just ordered a new harness and called it quits. When the headlights looked brighter with the new harness, I just accepted that and put the idea of relays out of my mind.
I have no immediate interest in adding relays to this car right now. I like the idea of adding LED headlights instead. My understanding is that their current draw is less than even the most basic sealed beams with far greater output. Sorta hard to beat that. I'm sure the prices will be stiff but hey...NO kids here so I don't mind!