For 1990-2009 cars

### Headlamps/Daytime Running Lamps (DRL)

Park, Marker, License, and Tail Lamps

When the headlamp switch is moved to the PARK or ON position, battery voltage is supplied from the 15A Park Lamp fuse to circuit 9. Current flows through circuit 9 to the instrument panel fuse block (IPFB). Battery power passes through the IPFB to both license lamps, both front and rear tail lamps, both front park/turn lamps, and all marker lamps through circuit 9. The front marker and front park/turn lamps are grounded by circuit 150 through the forward lamp ground splice pack. The rear tail lamps and license lamps are grounded by circuit 550 at the rear ground splice pack and the right rear body ground.

Daytime Running Lamps

Daytime running lamps are standard on all Saturn models. The DRL relay is located in the underhood fuse block (UHFB). The coil side of the DRL relay receives battery voltage. Current flows through the DRL relay coil to the body control module through circuit 592. The BCM will ground circuit 592 when DRL is required. The BCM uses ignition, park lamp, headlamp, high beam and park brake inputs to control DRL. The DRL will be enabled anytime the ignition is in the RUN position, the headlamp switch is Off, the park brake switch is Off (park brake not engaged and the gear selector is in any position but Park).

Battery voltage is supplied through the left headlamp fuse to circuit 40 to the left high beam lamp. Voltage flows through the left high beam lamp to the UHFB through circuit 1200. Current flows to the right high beam lamp from the UHFB through circuit 1200. Current flows through the right high beam lamp to the DRL relay located in the UHFB through circuit 593. The BCM provides ground to circuit 592 to energize the relay. Current flows through the closed contacts of the DRL relay to ground through circuit 150 to the forward lamp splice pack. This circuit results in both high beam lamps being connected in series, which allows the high beam lights to operate at half brightness.

The BCM will turn Off the DRL relay when it sees any of the following inputs:

• | Headlamps On

• | Parking brake On

• | Ignition not in the RUN position

• | Gear selector in Park

The BCM uses the high beam input to determine if the DRL functions are working. If the DRL functions are not operating properly a diagnostic trouble code may be set. Refer to Diagnosis in this section for further information.

Headlamps

Battery power is applied to the low and high beam elements of the left headlamp assembly by the 10A left headlamp fuse through circuit 40. Battery power is applied to the low beam element of the right headlamp assembly by the 10A right headlamp fuse through circuit 140. Battery power is applied to the right high beam element by the right headlamp fuse normally closed (DRL relay NOT energized) contacts of the DRL relay and circuit 593.

When the headlamp switch is turned to On, and the high beam switch is Off, a ground path is provided to circuit 1201 through the headlamp switch to circuit 350. Circuit 350 is grounded at I/P splice pack #2. When the high beam switch is in the ON position, a ground path is provided to circuit 1200 through the headlamp switch to circuit 350. Circuit 350 is connected to the instrument panel fuse block (IPFB) and is grounded I/P splice pack #2. This same operation is also true when the flash-to-pass feature is used. To operate the flash-to-pass feature, the headlamp switch lever is pulled toward the driver.

Stop Lamps

Battery voltage is applied at all times to the brake switch from the brake/park lock fuse through circuit 540. When the brake switch is closed (brake pedal pushed down) battery voltage is applied to the stop lamps through circuit 20. The stop lamps are grounded by circuit 550 through the rear body ground splice pack.

Turn Signals

When the ignition switch is turned to the RUN position, battery voltage is applied to the turn/hazard switch from the 10A turn signal fuse through circuit 139. This battery voltage is then applied to the turn lamp flasher module through circuit 1508.

During a left hand turn, battery voltage is supplied by the turn lamp flasher module through circuit 16, and applied to circuit 18 through the turn/hazard switch. Circuit 18 supplies voltage to the left rear turn lamp through the instrument panel fuse block. Circuit 1414 feeds the left turn telltale in the instrument cluster. Circuit 18 feeds voltage to the IPFB where it becomes circuit 14 and supplies voltage to the left front park turn lamp through the underhood fuse block.

During a right hand turn, battery voltage is supplied by the turn lamp flasher module through circuit 16, and applied to circuit 19 through the turn/hazard switch. Circuit 19 supplies voltage to the left rear turn lamp through the instrument panel fuse block. Circuit 1415 feeds the right turn telltale in the instrument cluster. Circuit 19 feeds voltage to the IPFB where it becomes circuit 15 and supplies voltage to the left front park turn lamp through the underhood fuse block.

The front park/turn lamps ground through circuit 150 to the forward lamp splice pack. The rear turn lamps ground through circuit 550 to the rear body splice pack.

Fog Lamps

Battery voltage is applied to the fog lamp switch from circuit 1200. The fog lamps will only come On when the headlamp switch is in the ON or PARK position, and the fog lamp switch has been pressed on. The fog lamps will not come On when the high beam headlamps are On. The fog lamp switch will energize the fog lamp relay by providing ground through circuit 317. This ground will also turn on the fog lamp indicator located in the fog lamp switch. When the fog lamp relay is energized, current will flow to the fog lamps through circuit 34. The fog lamps are grounded by circuit 150 through the forward lamp ground splice pack.

Hazard Lamps

Battery voltage is always applied from the 10A HAZARD fuse to the hazard switch through circuit 1040. When the hazard switch is pressed, battery voltage is fed through the timing circuitry inside the hazard switch. This voltage is fed to the right tail lamp and right front park turn lamp through circuit 19 and 15, and the left rear tail lamp and left front park/turn lamp through circuit 18 and 14. Both front park/turn lamps are grounded through circuit 150 at the forward lamp splice pack, and the tail lamps are grounded through circuit 550 at the rear ground splice pack.

#### Bulbs - Replacement Bulbs

EXTERIOR LAMPS | TYPE OR TRADE NUMBER | SATURN NUMBER
--- | --- | ---
HEADLAMPS |  |
HI BEAM | 9005 (HB3) | 9441732
LO BEAM | 9006 (HB4) | 9441733
FRONT PARK/TURN LAMPS | 3157 (SL/SW) | 12450004
| 3357 (SC) | 12450181
FRONT SIDE MARKER LAMPS |  |
| 168 | 9425542
STOP/TAIL LAMPS |  | 12450004
| 3157 | 9438848
REAR TURN LAMPS |  | 12450004
| 3157 | 9417866
REAR SIDE MARKER LAMPS |  |
| 194 | 9421330
BACK-UP LAMPS |  | 12450004
| 3157 | 9417866
LICENSE LAMPS |  |
| 168 | 9425542
CENTER HIGH-MOUNTED STOP LAMPS | PC175 921 | 9442441 9441956
FOG LAMPS |  |
| 880X | 09442876