I would follow the troubleshooting steps. 8L-129 has them in the service manual. It does look pretty straight forward. Check for shorts to ground. If you don't have a multi-meter they are pretty cheap at most auto parts stores. If you need to learn how to use it just PM and I will help you.
DOME LAMP CIRCUIT (CONTINUED)
When Monitored and Set Condition
² When Monitored: With the ignition on.
² Set Condition: The Body Control Module (BCM) reports a short to power, ground, or an open on the Dome
Lamp circuit.
POSSIBLE CAUSES
DOME LAMP CIRCUIT SHORT TO VOLTAGE
DOME LAMP CIRCUIT SHORT TO GROUND
DOME LAMP CIRCUIT OPEN
BODY CONTROL MODULE INTERNAL FAILURE
For a complete Interior Lamps Circuit Diagram, (Refer to 8 - ELECTRICAL/LAMPS/LIGHTING - INTERIOR - SCHEMATICS
AND DIAGRAMS).
Diagnostic Test
1. MEASURE THE RESISTANCE OF THE DOME LAMP CIRCUIT
Turn the ignition off.
Disconnect the BCM harness connector.
Disconnect the Dome Lamp harness connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Dome Lamp circuit between the BCM
harness connector and the Dome Lamp harness connector. (Dome lamp #3 pin to BCM C4 Pin 8)
Is the resistance below 5.0 ohms?
Yes >> Go to 2
No >> Repair the Dome Lamp circuit for an open.
Perform BODY VERIFICATION TEST.
ZH LAMPS/LIGHTING - INTERIOR - ELECTRICAL DIAGNOSTICS 8L - 129
DOME LAMP CIRCUIT (CONTINUED)
2. MEASURE THE VOLTAGE OF THE DOME LAMP CIRCUIT
Turn the ignition on.
Measure the voltage of the Dome Lamp circuit between the Dome
Lamp harness connector and Ground.
Is voltage present?
Yes >> Repair the Dome Lamp circuit for a short to battery.
Perform BODY VERIFICATION TEST.
No >> Go to 3
3. MEASURE THE RESISTANCE OF THE DOME LAMP CIRCUIT
Turn the ignition off.
Measure the resistance of the Dome Lamp circuit between the Dome
Lamp harness connector and ground.
Is the resistance below 10K ohms?
Yes >> Repair the Dome Lamp circuit for a short to ground.
Perform BODY VERIFICATION TEST.
No >> Replace the Body Control Module. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/BODY CONTROL/
CENTRAL TIMER MODUL - REMOVAL).