Bear your diagram is too small to read, but you don't hook the headlight relays to the light switch, you trigger them from the dimmer switch, what is it that you are doing, there?
That is how I wired my headlight relay system with dimmer switch acting as trigger switch for headlight relays. The high and low beam power supply to relays from battery/alternator to lamps are fused. I installed an under hood six fused circuit 100 amp power distribution block to supply power to headlight, choke, o2 sensor, remote power sensor for voltage regulator, and future electric radiator cooling fan circuits.
Lights are much brighter, charging voltage is now spot on.
