Do you have relays on your headlights? That alone really increases their brightness, takes a lot of the load off most of the power circuit going through the dash, and reduces or eliminates the discharge at idle. May be a good idea even with LEDs. Separate circuits with relays for any of the larger power draws that eliminate all the power going through the bulkhead connector and dash cures a lot of ills on our old dinosaurs. And may reduce the size of the alternator that you need as well as protect your under dash circuits.