[ka24deroadster]

On my truck and the wiring diagram there is a black wire that runs from the firewall junction block to the junction block next to the battery. There is a black/white wire that runs from the firewall junction block and splices into the red Power wire that runs from the battery to the firewall. The diagram for the cab does not have anything shown for the terminal to the black and black/white wires. What do these wires do? Where do they go to under the dash?