Headlights - Automatic Twilight Sentinel Cadillac Seville IV

DESCRIPTION

The twilight sentinel system automatically controls on-off operation of headlights, taillights, and instrument panel lights in response to ambient light intensity. A time delay control allows lights to remain on for a pre-selected period after ignition is turned off.

The system operates independently of the headlight switch. On models equipped with Daytime Running Lights (DRL), the twilight sentinel system controls both systems automatically. Twilight sentinel system operates when headlight switch is in OFF position, but ignition and twilight sentinel switches must be in ON position. Headlight switch operates exterior lights independently of twilight sentinel system.

OPERATION

Twilight sentinel system operates automatically when ignition is on, headlights are off, and twilight sentinel system is on. When turned on, twilight sentinel system automatically turns on exterior lights at dusk. At daybreak, twilight sentinel system will turn exterior lights off.

Twilight sentinel system provides a 30-second delay before switching lights on or off, thus preventing system from operating under sudden ambient lighting changes, such as passing through tunnels and exposure to bright lights at night.

AIR BAG PRECAUTIONS

Observe following precautions when working on vehicles equipped with Supplemental Inflatable Restraint (SIR) air bag systems

1. Before performing any instrument panel testing, diagnosis, or repair, disable SIR system by disconnecting negative battery cable and Yellow 2-pin connector at base of steering column.
2. To enable SIR system to power down, wait 20 minutes before making any repairs. System back-up power supply still retains enough voltage to deploy air bag for a short time after battery is disconnected.
3. To avoid accidental air bag deployment, avoid Yellow SIR wiring harnesses when trouble shooting, repairing, or replacing instrument panel components. All SIR wiring harnesses are Yellow.

HANDLING PRECAUTIONS

1. Discharge personal static electricity by momentarily touching metal grounding point on vehicle before touching electronic components.
2. DO NOT touch terminals on components or connectors using fingers or metal tools. When unplugging connectors, never let metal tool contact any exposed terminal.
3. Never jumper, ground, or use test probes on components or connectors unless specified in diagnosis. Always connect ground lead first.
4. DO NOT remove solid-state components from protective packaging until ready for installation. Touch packaging to ground before opening.
5. DO NOT bump or drop components. DO NOT put component on metal work bench, metal objects, or electrically operated components, such as radio, TV, or oscilloscope.

Components Possibly Damaged By ESD

1. ABS Controller.
2. Central Control Module (CCM).
3. Chime Module And Cruise Control Module.
4. Distributorless Ignition System (DIS) Module.
5. Electronic Instrument Cluster Panel (IPC).
6. Electronic Control Module (ECM) (Including PROM, CAL-PAK, Or MEM-CAL).
7. HVAC Electronic A/C-Heater Controllers And Modules.
8. Power Control Module (PCM).
9. Radio And Theft Deterrent Modules.
10. Twilight Sentinel Module Or Amplifier.

Lights Do Not Turn On In Darkness

Loose connection at headlight switch or amplifier connector. Open wiring between fusible link and headlight switch. Inoperative headlight switch or circuit breaker. Open in ground path through on-off switch of time-delay control of sentinel switch. Inoperative photocell or amplifier.

Lights Do Not Turn Off In Daylight

Inoperative photocell or amplifier. Poor contact between photocell and socket, or socket disengaged from mounting hole. Obstructed photocell.

Lights Do Not Turn Off After Ignition Is Off

Fuse blown. Inoperative time delay control. Open wiring. Inoperative amplifier. Malfunctioning photocell.

Lights Do Not Stay On Proper Time Span After Ignition Is Off

Inoperative time delay control. High resistance at amplifier connector. Short in wiring. Inoperative amplifier.

Warning Chime Does Not Operate

Open wire in chime circuit. Inoperative door jam switch. Poor connection at headlight switch. Inoperative amplifier. Blown fuse. Time delay control malfunction.

TESTING

TWILIGHT SENTINEL SYSTEM OPERATION TEST

Note. Twilight sentinel lighting system should work properly when manually operated under following conditions: twilight sentinel control is in ON position (between MIN and MAX), headlight switch is in OFF position, and photocell is uncovered. Before testing, check all fuses for continuity.

Note. Unless otherwise specified, make all measurements using a digital volt-ohmmeter with an input impedance of 10 megohms.

See appropriate TEST PROCEDURE.

SYSTEM CHECK (WITHOUT DRL) - TEST PROCEDURE

1. Turn ignition, twilight sentinel, and headlights off. If exterior lights are off, go to next step. If exterior lights remain on, go to «TEST "B" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-b-test-procedure) .
2. Turn ignition on. Turn headlights off. Turn twilight sentinel on. Cover photocell on top of instrument cluster using dark paper. Exterior lights should turn on after about 30 seconds. If lights do not come on, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .
3. Uncover photocell. Expose photocell to sunlight or bright incandescent. Exterior lights should go off after about 45 seconds. If lights do not turn off, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .
4. Cover photocell. Wait for lights to come on. Turn ignition off. Set twilight sentinel control to MAX delay position. Lights should turn off after about 3 minutes. If lights turn off, system is working properly. If lights do not turn off, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .

SYSTEM CHECK (WITH DRL) - TEST PROCEDURE

1. Turn ignition, twilight sentinel, and headlights off. If exterior lights are off, go to next step. If exterior lights remain on, go «TEST "B" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-b-test-procedure) .
2. Turn headlights off. Set gear selector to Park position. Turn ignition on. If headlights and exterior lights are off, go to next step. If headlights and exterior lights come on, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .
3. Expose photocell to sunlight or bright incandescent light. Set gear selector to Drive position. If DRL headlights are on and exterior lights are off, go to next step. If headlights are off and/or exterior lights are on, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .
4. Set gear selector to Park position. Turn ignition on. Turn headlights off. Turn twilight sentinel on. Cover photocell using dark paper. If exterior lights turn on after about 30 seconds, go to next step. If exterior lights do not turn on after about 30 seconds, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .
5. Set twilight sentinel control to MAX delay position. Turn ignition off. If exterior lights turn off, system is working properly. If exterior lights do not turn off after about 3 minutes, go to «TEST "F" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-f-test-procedure) .

TEST "B" - TEST PROCEDURE

1. Unplug connectors from headlight switch. If lights remain on, go to next step. If lights are now off, go to step 7).
2. If headlights and body lights are on, go to appropriate ANTI-THEFT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT. If headlights only are on, go to next step. If body lights only are on, check and repair short to voltage in body light circuit.
3. If high beam headlights are not only lights on, go to next step. If only high beams are on, check for short to voltage in high beam circuit, or shorted dimmer switch.
4. Set dimmer switch to high beam position. If high beams are on and low beams are off, go to next step. If headlight beams are not as specified, go to step 6).
5. Unplug headlight relay "D", located in engine compartment micro relay center, on left wheelwell. Measure resistance between connector terminal No. 2 (Yellow wire) and ground. If resistance is not less than 10 ohms, check Yellow wire for short to voltage. If resistance is less than 10 ohms, repair short to ground in Light Blue wire. If wires are okay, replace relay.
6. Unplug headlight relay "E", located in engine compartment micro relay center, on left wheelwell. Measure resistance between connector terminal No. 2 (Light Green/Black wire) and ground. If resistance is less than 10 ohms, repair short to ground in Light Green/Black wire. If resistance is not less than 10 ohms, check Tan wire for short to voltage. If wires are okay, replace relay.
7. Unplug twilight sentinel/DRL module from headlight switch. Reconnect wiring to headlight switch. If lights are not on, replace module. If lights are still on, replace headlight switch.

TEST "C" - TEST PROCEDURE

1. Turn headlights on. Set dimmer switch to high beam position. If high beam headlights are not on, go to next step. If high beams are on, check dimmer switch. If dimmer switch is okay, repair Tan wire.
2. Turn ignition on. Cover photocell. Turn twilight sentinel on. If headlights come on, go to next step. If headlights do not come on, replace headlight switch.
3. Unplug headlight relay "D", located in engine compartment micro relay center, on left wheelwell. Check for battery voltage at relay connector terminals No. 1 (Orange wire) and No. 3 (Orange wire). If battery voltage exists at each terminal, go to next step. If battery voltage does not exist, repair appropriate Orange wire.
4. Measure resistance between relay connector terminal No. 2 (Light Blue wire) and ground. If resistance is less than 3 ohms, go to step 6). If resistance is not less than 3 ohms, go to next step.
5. Unplug headlight switch connector. Install headlight relay "D". Check for battery voltage at switch connector C1 terminal "C" (Light Blue wire). (Scheme 1)-4. If battery voltage exists, check Black wire from connector C2 terminal "A" for open circuit. If Black wire is okay, replace headlight switch. If battery voltage does not exist, repair open circuit in Light Blue wire.
6. Connect fused jumper between headlight relay "D" terminals No. 3 and 5. If headlights do not come on, go to next step. If headlights come on, replace relay "D".
7. With jumper in place, check for battery voltage at terminal C5 (Yellow wire) at 48-pin connector left of steering column. If battery voltage exists, replace dimmer switch. If battery voltage does not exist, check jumper wire and fuse.

Scheme 1

Scheme 2

Scheme 3

Scheme 4

TEST "F" - TEST PROCEDURE

1. Remove headlight/twilight sentinel switch. See «HEADLIGHT/TWILIGHT SENTINEL SWITCH»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Unplug headlight switch connectors. Reconnect battery. Using DVOM, measure voltage between headlight switch connector C1 terminal "A" (Orange wire) and ground. (Scheme 1)-4. If battery voltage does not exist, repair Orange wire between trunk compartment fuse block and headlight switch connector. If battery voltage exists, go to next step.
2. Turn ignition off. Measure voltage at headlight switch connector C1 terminal "B" (Pink/Black wire). If battery voltage exists, repair short to battery voltage in Pink/Black wire. If voltage does not exist, turn ignition on. Measure voltage at headlight switch connector C1 terminal "B" (Pink/Black wire). If voltage now exists, go to step 3). If voltage does not exist, repair Pink/Black wire.
3. Measure resistance between terminals "J" (Black wire) and "H" (White wire) of headlight switch connector C1. Cover photocell, and record resistance. Uncover photocell, and record resistance with photocell exposed to bright incandescent light or sunlight.
4. Resistance should be greater than 90,000 ohms with photocell covered and less than 72,000 ohms with photocell exposed to light. If resistance is not as specified, go to «TEST "L" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-l-test-procedure). If resistance is as specified, measure resistance between headlight switch connector C1 terminal "H" (White wire) and ground.
5. If resistance is less than 100,000 ohms, go to «TEST "L" - TEST PROCEDURE»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel__test-l-test-procedure). If resistance is greater than 100,000 ohms and vehicle is equipped with daytime running lights, go to next step. If resistance is greater than 100,000 ohms, and vehicle is not equipped with daytime running lights, see appropriate STEERING COLUMN SWITCHES article in the ACCESSORIES/SAFETY EQUIPMENT Section.
6. Using DVOM, measure voltage at headlight switch connector C1 terminal "L" (Light Green/Black wire). Set gear selector to Park position. Record voltage. Set gear selector to Drive position. Record voltage. Battery voltage should exist with selector in Park position; no voltage should exist with selector in Drive position.
7. If voltages are as specified, go to next step. If voltages are not as specified, repair Light Green/Black wire between headlight switch connector and transaxle position switch. If wire is okay, replace transaxle position switch.

TEST "L" - TEST PROCEDURE

1. Reconnect headlight switch. Remove twilight sentinel photocell. See «TWILIGHT SENTINEL PHOTOCELL»(/cadillac/seville/iv-1992-1997/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Unplug photocell harness connector. Turn ignition on. Measure voltage at photocell harness connector terminal "A" (White wire).
2. If voltage is not 5 volts, repair White wire between photocell and headlight switch connector C1 terminal "H". If voltage is 5 volts, measure voltage between photocell harness connector terminals. If voltage is not 5 volts, repair open in Black wire between photocell and headlight switch connector C1 terminal "J". If voltage is 5 volts, replace photocell.

REMOVAL & INSTALLATION

Disconnect negative battery cable. Remove headlight switch module from instrument panel by carefully pulling out on switch knob while prying on opposite side of module. Unplug connector. To install, reverse removal procedure.

Depending on model, photocell is either mounted under left defroster grille or secured to top of instrument panel. Unsnap defroster grille. Twist photocell counterclockwise to disengage photocell and socket. Unplug connector. To install, reverse removal procedure.

Wiring Diagram. Scheme 5

See also:
• AIR BAG PRECAUTIONS
• TEST "B" - TEST PROCEDURE
• TEST "F" - TEST PROCEDURE
• HEADLIGHT/TWILIGHT SENTINEL SWITCH
• TEST "L" - TEST PROCEDURE