So it's finally, really, totally finished. I have constant low beams and high beams when I activate them.
But, the simplified harness I drew today didn't work. The high beam circuit didn't have enough power to activate the solenoids. constant low beams, but no high beam activation. I guess that the ground signal just wouldn't overcome the resistance of the solenoids when the low beam ground was handy with basically no resistance.
So I started investigating. High and low filaments of H4 bulbs have about 3-4 Ohms resistance. the relays I am using have about 65 Ohms.
I couldn't measure the resistance of thesolenoids however... since they only close when they have power going through them. I guess I could have measured voltage drop and calculated the resistance if I felt scientific, but I am strictly in engineering mode on this so I didn't care. (Scientists try to understand everything about their experiment; engineers jsut want to make things work.)
So, I decided I would just go back to using a second pair of relays to isolate the solenoid circuit with another lead off of the battery. I am using single fused leads for the ballasts, but I figured on shared fuse for the solenoids is fine, since I don't need one if I lose the other anyway.
My first attempt was pretty awesome. It didn't have any captured grounds... it just worked backwards.
Low beams ran the highs and high beams only ran lows. Never did figure out why. So, back to the drawing board... and I finally had the epiphany I had been searching for.
I don't need to use the low beam ground
at all. The whole point of the low ground is so you can have it switched off when you use high beams... which I don't want. So I moved the ballast circuit ground from the switched low beam ground to a constant ground. Since the hot feed only works when you move the rotary switch on, the extra ground is redundant. That greatly simplified everything, because now I just had to make the other circuit close the solenoids when the high beam ground was switched on.
Man this was a pain in the ass, but in the end it's worth it I guess.
