Strange headlight/instrument light problem

OCTODIGITUS

MEMBER
2000 TOYOTA COROLLA
4 CYL
2WD
AUTOMATIC
150,000 MILES

My car's instrument panel light bulb isn't turning on. The warning lights (seat belt, etc) still work but not the light behind the gauges. The headlights work normally for the first 10 or so seconds the car is on, switching between the DRL's and the low beams. After those ten seconds, only the low beams work, and I can't shut the lights off at all. I checked all fuses and they're all fine. Could this be a headlight relay? Thanks.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Welcome to 2CarPros.

The idea that the relay could be an issue doesn't see logical for me because the relay doesn't power the instrument panel as you described. I have to be honest, I feel the switch is bad. However, even the light sensor could be causing the headlamps to turn off.

Here are directions for testing both. Let me know what you find. The attached pictures correlate with the directions.

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2000 Toyota Corolla CE Sedan L4-1.8L (1ZZ-FE)
Component Tests and General Diagnostics
Vehicle Sensors and Switches Sensors and Switches - Lighting and Horns Headlamp Switch Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS

pic 1

INSPECT AUTOMATIC LIGHT CONTROL
a. Turn the ignition switch ON.
B. Turn the light control switch to OFF.
C. Parking brake lever released.
D. Gradually cover the top of the sensor.
E. Verify that the lights should turn ON the accessory lights and the headlights.

Pic 2

INSPECT AUTOMATIC LIGHT CONTROL
a. Turn the ignition switch ON.
B. Turn the light control switch to OFF.
C. Parking brake lever released.
D. Cover the top of the light sensor.
E. Head and tail lights turn ON.
F. Gradually expose the light sensor.
G. Tail light turn OFF and DRL light turn ON.

INSPECT LIGHT-OFF CONDITION
a. Turn the ignition switch ON.
B. Turn the light control switch to OFF.
C. Parking brake lever released.
D. Lights auto ON:
Gradually cover the top of the sensor.

INSPECT LIGHTS-ON CONDITION
Turn the ignition switch OFF.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR CIRCUIT

pic 3

pic 4

a. Disconnect the connector from the sensor and inspect the connector on the wire harness side, as shown in the chart.

If circuit is as specified, perform the inspection on the following.
If the circuit is not as specified, inspect the circuit connected to other parts.

Pic 5

pic 6

b. Connect the wire harness side connector to the sensor and inspect wire harness side connector from the back side, as shown.

HINT:
- Ignition switch ON.
- Light control switch AUTO.
- Vehicle's surroundings are bright.

If circuit is as specified, try replacing the sensor with a new one.
If the circuit is not as specified, inspect the circuit connected to other parts.

______________________________

Let me know what you find.

Joe

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