Interior Lamps
The interior lighting consists of the dome lamp.
Dome Lamp
The DOME PANEL circuit breaker in the instrument panel (IP) fuse block
supplies battery positive voltage to the dome lamp. A path to ground is provided
for the dome lamp through the IP lamps dimmer switch or the door jamb switch.
When the driver places the IP dimmer switch in the dome lamp ON position
or opens the driver's door, the dome lamp will illuminate.
Interior Lamps Dimming
This group includes incandescent lamps which may be dimmed. The following
lamps are part of this group:
| • | The HVAC control head assembly |
| • | The instrument panel cluster (IPC) |
| • | The seat belt alarm, if equipped |
| • | The trailer marker lamps switch, if equipped |
| • | The various transmission control switches |
The DOME PANEL circuit breaker in the instrument panel (IP) fuse block
supplies battery positive voltage to the headlamp switch. When the headlamp
switch is placed in the PARK or HEADLAMP position, battery positive voltage
is supplied to the IP dimmer switch. The IP dimmer switch has a variable
resistor inside of it. The setting of the variable resistor will determine
the amount of voltage drop across it. The IP dimmer switch then supplies
voltage to splice 221. Splice 221 distributes the voltage to all of the lamps
listed above. All of the lamps listed above, with the exception of the PRNDL
indicator lamp, are grounded at G101 or G111. The PRNDL indicator lamp has
a case ground.
Driver Controls and Modules
Driver controls include the following components.
| • | The hazard switch/hazard warning switch |
| • | The headlamp dimmer switch |
| • | The trailer marker lamps switch, if equipped |
| • | The trailer stop lamp switch, if equipped |
There are three modules involved with the lighting system:
| • | The daytime running lights (DRL) control module |
| • | The transmission control module (TCM) |
| • | The transmission control module (TCM) interface module |