For 1990-2009 cars

### Turn Lamps

With the ignition switch in the RUN position, battery positive voltage (B+) is supplied from the IP fuse block T/SIG/BU LP/BTSI fuse 1B via CKT 539 (PNK) through the turn signal flasher to the normally closed switch in the turn/hazard switch via CKT 16 (PPL). With the turn switch in the left turn position, battery positive voltage (B+) is applied through the turn switch and two paths to the turn lamps. One path is to the left front park/turn lamps and the side marker lamps via CKT 14 (LT BLU). The second path is supplied to the left tail/stop/turn lamps via CKT 18 (YEL). The lamps go on immediately. The lights begin to flash when the current heats up the timing element in the flasher, and the flasher repeatedly opens and closes the circuit. A similar procedure is followed when the turn switch is in the right turn position. Battery positive voltage (B+) is supplied to the right front park/turn lamps and the side marker lamps via CKT 15 (DK BLU). Battery positive voltage (B+) is supplied to the right tail/stop/turn lamps via CKT 19 (DK GRN).

### Hazard Lamps

Battery positive voltage (B+) is supplied at all times from the IP fuse block BRK/HZRD LPS fuse 6B via 140 (ORN). The current flows through the hazard flasher to the normally open switch in the turn/hazard switch. With the hazard switch in the ON position, battery positive voltage (B+) is applied through the turn/hazard switch to all four paths used by the left and right turn lamps. The following components flash on and off:

• | All turn lamps

• | Both indicators

With the hazard switch in the ON position, the turn circuit is always open, and the hazard flasher controls the lamps.

### Stop Lamps (Oldsmobile/Buick)

Battery positive voltage (B+) is supplied at all times from the IP fuse block BRK/HZRD LPS fuse 6B via 140 (ORN) to the stoplamp/BTSI switch. When the brake pedal is pressed, battery positive voltage (B+) is applied through the stoplamp/BTSI switch via CKT 17 (WHT) and the turn/hazard switch via CKT 18 (YEL) and CKT 19 (DK GRN) to the stop lamps. This causes the stop lamps to light.

### Stop Lamps (Pontiac)

Battery positive voltage (B+) is supplied at all times from the IP fuse block BRK/HZRD LPS fuse 6B via CKT 140 (ORN) to the stoplamp/BTSI switch. When the brake pedal is pressed, battery positive voltage (B+) is applied through the stoplamp/BTSI switch via CKT 20 (LT BLU) to the stoplamps. This causes the stoplamps to light.

### Park Lamps (Buick)

When the headlamp switch is in the PARK position, the park lamps input to the lamp control module (LCM) is grounded via CKT 308 (GRY/BLK). The LCM then supplies battery positive voltage (B+) via CKT 256 (PPL) through the PARKLAMP fuse 8C to the front side marker, front park/turn lamp, tail, rear side marker and license lamps via CKT 9 (BRN). When the ignition switch is in the RUN position and the ambient light sensor indicates darkness, the LCM provides battery positive voltage (B+) to the park lamps, regardless of the position of the headlamp switch.

### Park Lamps (Oldsmobile)

Battery positive voltage (B+) is supplied at all times from the IP fuse block PARK/LPS/INT LPS fuse 6C to the headlamp switch, lamp control module (LCM), and RH IP fuse block park lamp relay position K via CKT 240 (ORN). With the headlamp switch in the PARK or HEAD position, battery positive voltage (B+) is supplied to the coil of the RH IP fuse block park lamp relay position K via CKT 74 (LT BLU) which is permanently grounded to G201 via CKT 1450 (BLK). The coil is energized and the contacts close, providing battery positive voltage (B+) to the front side marker, front park/turn, tail, rear side marker, and license lamps via CKT 9 (BRN). When the ignition switch is in the RUN position and the ambient light sensor indicates darkness, the LCM provides battery positive voltage (B+) to the park lamps, regardless of the position of the headlamp switch.

### Park Lamps (Pontiac)

Battery positive voltage (B+) is supplied at all times from the IP fuse block PARK LPS/INT LPS fuse 6C to the headlamp switch and lamp control module (LCM) via CKT 240 (ORN). With the headlamp switch in the PARK or the HEAD position, battery positive voltage (B+) is supplied to the front side marker, park/turn, tail, rear side marker, and license lamps via CKT 9 (BRN). When the ignition switch is in the RUN position and the ambient light sensor indicates darkness, the LCM provides battery positive voltage (B+) to the park lamps, regardless of the position of the headlamp switch.

### Cornering Lamps (Buick)

When the park lamps are on, battery positive voltage (B+) is supplied from the IP fuse block PERIMETER LT fuse 8A to the turn/hazard switch via CKT 1654 (TAN). The left cornering lamp is permanently grounded to G104 via CKT 1150 (BLK). The right cornering lamp is permanently grounded to G105 via CKT 1550 (BLK). With the turn switch in the left turn position, battery positive voltage (B+) is supplied through the turn/hazard switch via CKT 57 (ORN) to the left cornering lamp. With the turn switch in the right position, battery positive voltage (B+) is supplied through the turn/hazard switch via CKT 58 (BLK) to the right cornering lamp.

### Cornering Lamps (Oldsmobile)

With the ignition switch in the RUN position, battery positive voltage (B+) is supplied from the IP fuse block T/SIG/BU LP/BTSI fuse 1B to the turn/hazard switch via CKT 539 (PNK). The left cornering lamp is permanently grounded to G104 via CKT 1150 (BLK). The right cornering lamp is permanently grounded to G105 via CKT 1550 (BLK). With the turn switch in the left turn position, battery positive voltage (B+) is supplied through the turn/hazard switch via CKT 57 (ORN) to the left cornering lamp. With the turn switch in the right turn position, battery positive voltage (B+) is supplied through the turn/hazard switch via CKT 58 (BLK) to the right cornering lamp.

### Perimeter Lighting (Buick)

Refer to Headlights Circuit Description