Part 2 of 4
BRAKE LAMP SWITCHThe plunger type brake lamp switch is mounted on a bracket attached to the brake pedal support.
CAUTION: The switch can only be adjusted during initial installation. If the switch is not adjusted properly a new switch must be installed.
The primary function of the switch is to turn ON the brake lamps during braking. The switch is also used to send signals to components that must know when the brakes are applied, such as the Powertrain Control Module (PCM), which uses the signal to cancel speed control. The CAB uses the brake switch signal to monitor brake pedal application. When the switch contacts open (brakes applied), the CAB receives the brake applied signal. The CAB then monitors the RWAL system to anticipate the need for an RWAL stop.
Fig. 4 Combination Flasher:
COMBINATION FLASHER
The combination flasher is located in a dedicated connector on a take out of the instrument panel wire harness, located under the instrument panel just outboard of the instrument panel steering column opening. The combination flasher is a smart relay that functions as both the turn signal system and the hazard warning system flasher. The combination flasher has fourteen blade-type terminals that connect it to the vehicle electrical system through fourteen matching cavities in the instrument panel wire harness connector; however, only ten of the combination flasher terminals are used in this application. The combination flasher contains active electronic Integrated Circuitry (IC) elements. This flasher is designed to handle the current flow requirements of the factory-installed lighting. If supplemental lighting is added to the turn signal lamp circuits, such as when towing a trailer with lights, the combination flasher will automatically try to compensate to keep the flash rate the same.
The combination flasher cannot be repaired or adjusted and, if faulty or damaged, it must be replaced.
The combination flasher has fourteen blade-type terminals, but only ten are used in this application. These ten terminals are intended for the following inputs and outputs: fused B(+), fused ignition switch output, right turn signal sense, left turn signal sense, hazard flasher signal, brake lamp switch output, and two outputs each for the right and left turn signal circuits. Constant battery voltage is supplied to the flasher so that it can perform the hazard warning function, and ignition switched battery voltage is supplied for the turn signal function. The Integrated Circuit (IC) within the combination flasher contains the logic that controls the flasher operation and the flash rate. The IC receives separate sense ground inputs from the multi-function switch for the hazard flasher, right turn signal, and left turn signal. A special design feature of the combination flasher allows it to "sense" that a turn signal circuit or bulb is not operating, and provide the driver an indication of the condition by flashing the remaining bulbs in the affected circuit at a higher rate (120 flashes-per-minute or higher). Conventional flashers either continue flashing at their typical rate (heavy-duty type), or discontinue flashing the affected circuit entirely (standard-duty type).
Because of the active electronic elements within the combination flasher, it cannot be tested with conventional automotive electrical test equipment. If the combination flasher is believed to be faulty, test the turn signal and hazard warning system. Then replace the combination flasher with a known good unit to confirm system operation. (Refer to TURN SIGNAL & HAZARD WARNING SYSTEM - DIAGNOSIS AND TESTING).
HEADLAMP UNIT
Headlamps on the Durango are modular in design. The turn/park lamp module is incorporated into the headlamp module. The module contains four bulbs; a dual filament headlamp bulb, two dual filament turn/ park bulbs, and a side marker bulb.
Headlamps and parking lamps are controlled by the headlamp switch. The multi-function switch mounted on the steering column controls the high beam function, and the turn signal function.
HEADLAMP SWITCH
The headlamp switch is located in the instrument panel, outboard of the steering column. It closes a path to ground for the Central Timer Module (CTM) when the park or head lamps are ON and the driver door ajar switch is closed (driver door is open). The headlamp switch opens the ground path when the headlamp switch is turned OFF. The ground path is also opened when the driver door ajar switch is open (driver door is closed). This switch also contains a rheostat for controlling the illumination level of the instrument cluster lamps.
The headlamp switch cannot be repaired and, if faulty or damaged, it must be replaced.
The headlamp switch has an OFF position, a parking lamp position, and a headlamp ON position. High beams are controlled by the multifunction switch on the steering column. The headlamp switch cannot be repaired. It must be replaced.