Missing 12 Pin Connector

[muledalton]

Do I use the circuit breaker or is the circuit breaker just for a (4) 12 volt battery setup?

use breaker between power and switch

[Sergio]

It is hard to see some of the details on the picture, but the #8 bullet connector should plug to the bullet connector on your first picture.
That bullet connector in the dashboard brings the +48v from the key switch (cold side) to the harness. If you follow the wire it should go to the trigger wire in your voltage reducer. That will turn the reducer on and off with the key switch.
You already have 2 fuses, 1 large one in the #1 wire which is there to protect the wiring in the harness and a smaller one by the voltage converter which is there to somewhat protect the voltage converter.
I am not sure what the intended use for that breaker is, if the kit did not come with any instructions, is there a 5/16 ring connector at the end of #6 or what are the specs printed on the breaker?

found this photo... it has the breaker for the Precedent brake lights

i found the install instructions for Precedent light kits