When rewiring my 50 chev pu 6v system I opted for the use of relays mounted on the firewall with the dimmer switch controlling power to the relays and the dash switch to control power to the dimmer switch. I used my own idea for a terminal block made of 1 inch thickness plastic which I modified. So I have been happy with the changes and encourage you to do the same. I like the idea of troubleshooting the problem with the least effort so no time and money is wasted. You will find the solution.....good luck
