The fuse block is mounted to the firewall, inside the truck, to the left of the steering column. The turn signal flasher and the hazard warning flasher plug into the fuse block. Each fuse receptacle is marked as to the circuits it protects and the correct amperage. In-line fuses are also used to protect some circuits. These are: 1969-75 ammeter, and 1975-82 underhood light and air conditioning system.
A special heavy duty turn signal flasher is required to properly operate the turn signals when a trailer's lights are connected to the system.