I don't know if this helps, but I took a different route. My stock turn signals weren't wired for 4-way flashers, and I decided not to chop into the wires to make it that way. The signals have no power when the ignition is off, which makes them useless for breakdowns, etc. What I did instead was tap into the cigarette lighter hot lead (straight off the battery), installed a switch, fuse, and flasher under the dash, and spliced into the brake wire after the brakelight switch. Sure the front lights don't flash, but I can shut off the truck and the rear lights flash brightly.
