All that is not required. If it's a true relay kit, it takes its power directly from the battery. The headlight power is only used to close the relay, and that only takes ~ 0.1V. Even on DRL dim the stock lights use about 10V. If you didn't disable your DRL's, then a relay kit should eliminate this problem altogether. You probably tapped power itself from the headlight wiring, thats why you had flickering.