Brake Lamp: Description and Operation

CIRCUIT OPERATION
Stop Lamps And CHMSL Lamps
Circuit A3 from fuse 6, a 40 amp, in the Power Distribution Center (PDC) supplies voltage to circuit F32 through fuse 20, a 20 amp, in the fuse block. Circuit F32 connects to the stop lamp switch.

When the operator presses the brake pedal, the stop lamp switch CLOSES and connects circuit F32 to circuit L50. Circuit L50 connects to the Center High Mounted Stop Lamps (CHMSL) and multi-function switch. The multi-function switch supplies power to the L62 and L63 circuits. Circuit L62 powers the right stop lamp. Circuit L63 powers the left stop lamp.

Ground Circuit
Circuit Z13 provides a ground for the stop lamps and back-up lamps. The Z13 circuit has more than one branch. Circuit Z13 also supplies ground path for the tail lamps, parking lamps, rear license plate lamp, back-up lamps, and turn signals. Circuit Z3 provides ground for the CHMSL lamps.