Hey Guys Me n CumminsHP are doing an 85 crewcab with a 90 drivetrain and we did a custom wiring harness. But it's based off the 90's harness in some ways. Anyway uh the brake light system is confusing us, Umm the brake light switch sends power into the signal light switch n then out from there so it cuts out the rear signal light n sends a constant DC power for the rear brakes. If I can't get it to work can I use two 12V diodes on the signal wires n connect in a seperate brake light wire to each side past the diode should keep the front signal flashing as well as the rear but solid and flashing both.

Or tie the signal wire into the park light wire with a Diode in the park light wire and run the rear brake light on a completely seperate element in the bulb?