SEO 6J7 provides a high-beam headlamps flashing module, rear lamps flashing and control wire for a customer-furnished switch to turn the module on or off. The flasher control wire is coiled under the center of the instrument panel. This control lead may be combined with the interior wiring leads for SEO 6J3 when that option is ordered with SEO 6J7.

The headlamps flashing module is located below the passenger side front headlamp and forward of the passenger side front wheel. The module is connected to an inline connector in the forward lamp harness. The headlamps flashing module is activated by the application of 12 volts to a dark green/red wire coiled in the passenger side footwell. When activated, the driver and passenger side high-beam headlamps and the high-beam instrument panel cluster light will flash alternately at 2.4 flashes per second.

When the headlamps flashing module is turned on, the module sends a signal to the Body Control Module (BCM). The BCM alternately flashes the stop lamps and backup lamps. Depressing the brake pedal will override the stop lamp flashing and placing the transmission in reverse will override the backup lamp flashing.

During daylight conditions, the Daytime Running Lamps (DRL) are automatically turned off whenever the headlamps flasher module is activated. During nighttime conditions, the low-beam headlamps turn on automatically while the high-beam headlamps flash. Turning on the high-beam headlamps manually with the turn signal/multifunction lever will override the flashing module and the high-beam headlamps will operate continuously.

A 20 amp fuse protects the flasher module circuit. This fuse is located in the underhood fuse block in the engine compartment on the driver side of the vehicle and is labelled HEADLAMP WASH. See "Underhood Fuse Block" in the Service and Appearance Care section of the Tahoe owner's manual for more information.

When it is dark outside, the taillamps will turn on automatically. The Center High-Mounted Stoplamp (CHMSL) will not flash and will operate only when the regular brake pedal is pressed.