TrailBlazer 2WD L6-4.2L VIN S (2003)
Brake Lamp: Description and Operation
STOP LAMPS
The STOP fuse in the engine wiring harness junction block supplies battery positive voltage to the normally open stop lamp switch. When the driver
presses the brake pedal, the switch contacts close and battery positive voltage is supplied to both the VEHICLE STOP fuse and the VEHICLE CHMSL
fuse. The current flow is now to the stop lamps which are grounded at G401 and G402. The center high mounted stop lamp (CHMSL) is grounded at
G401.
For trailer wiring, a separate stop lamp circuit is connected through the GMSF to the trailer wiring harness.
