These guys have a good headlight relay kit for $25. No wiring changes. You hook it to the battery and the headlights, and then plug into the OEM headlight connector. And the harness wiring is long enough for our trucks. It's like a 5-minute install. I have been referring this site for 3-1/2 years, since I put mine on, and everybody said the relay is garbage, it will fail, etc. No issues in 3-1/2 years, and I do a fair amount of driving with the lights on, and switching high-beam to low-beam often on the snaky roads around here. No issues. Search on the page for Halogen Headlight Brightener, then figure out which one matches your headlight style numbers (9005, H4, etc.).
http://www.autolumination.com/headlights.htm
With regard to the dash lights, you do have the grounding strap from the firewall of the cab to the passenger side engine head, right? If you don't, that could be the problem.