rear wiring

I am replacing the wiring in my 1983 K20. I decided to reuse the original rear wiring and cut the wires at the front and tried to connect everything. My problem is there are 4 original wires an the universal has 5. I have the 2 signals and the reverse ok but cant figure out the rear park and the brake lights can anyone help.

I am replacing the wiring in my 1983 K20. I decided to reuse the original rear wiring and cut the wires at the front and tried to connect everything. My problem is there are 4 original wires an the universal has 5. I have the 2 signals and the reverse ok but cant figure out the rear park and the brake lights can anyone help.

Hi,
If you have the signals, they are also the brake lights. Could the extra wire be backup lights?
The parking lights would take one wire to feed both sides.

Bob B