1997 Dodge caravan. Dome lights(2) and tailgate courtesy lights(2) do not turn on. with either 1.opening the tailgate; 2. opening any other door ; 3. using the in dash switch. Trouble shooting: 1 Checked all bulbs. O.K.; 2. checked all fuses in the BCM as well as the fuse/relay module under the hood.; 3.Wiring diagram shows a "Courtesy Light Relay." I haven't found it anywhere in the vehicle. Is there one? Where is it in the vehicle? Other suggestions,please.

If the dome lights in your 2009 Cadillac CTS are not turning off, it can be a frustrating issue. Here are some steps to diagnose and potentially fix the problem:
1. **Manually Turn Off the Dome Lights:**
- In most vehicles, including the Cadillac CTS, there's typically a manual switch on or near the dome light itself. Ensure this switch is in the "Off" position.
2. **Check for Open Doors:**
- Make sure all doors, including the trunk and the hood, are completely closed. Sometimes, a door ajar can prevent the dome lights from turning off.
3. **Interior Light Dimmer Control:**
- Check the position of the interior light dimmer control, which is usually located on the headlight switch or dashboard. If it's turned all the way up, it may keep the dome lights on. Adjust it to the lowest setting.
4. **Ignition Switch:**
- Ensure the ignition switch is in the "Off" position. Sometimes, if the ignition switch is left in the "Accessory" position, the dome lights may stay on.
5. **Faulty Door Switches:**
- Each door usually has a door switch that signals the lights to turn on when a door is opened and off when it's closed. One of these switches may be malfunctioning. You can try manually pressing and releasing each door switch to see if the lights respond.
6. **Battery Disconnect and Reconnect:**
- If the above steps don't work, you can disconnect the vehicle's battery for a few minutes and then reconnect it. This can sometimes reset the electrical system and resolve the issue.
7. **Consult the Owner's Manual:**
- Refer to your Cadillac CTS owner's manual for specific information about the dome light controls and troubleshooting tips.
8. **Professional Diagnosis:**
- If the issue persists, it may be related to a more complex electrical problem. In this case, it's advisable to consult a professional mechanic or an auto-electrician to diagnose and repair the problem.
It's important to be patient and methodical when troubleshooting this issue, as it can have various causes. If you're not comfortable working on the electrical system of your vehicle, seeking professional help is a wise choice to avoid further complications.

The dome lamp switch has 3 positions: DOOR, OFF, and ON. When in the DOOR position, the dome lamp operation is controlled by the body control module (BCM).The ON position provides a ground for continuous operation. Ground is provided at G302. The OFF position turns OFF any dome lamp operation. The courtesy lamps, may be manually turned ON by placing the instrument panel (I/P) dimmer switch in the DOME position. When the dome lamp switch is in the DOOR position, the dome lamp will illuminate when a door is opened. When a door is opened, the courtesy lamps turn ON. After all the doors have been closed, the courtesy lamps will remain illuminated approximately 10 seconds after the last door closes. When the driver places the dome lamp switch in the OFF position, the dome lamp will be disabled.

Do you hear any chimes when the light comes on ? Door ajar switch problem , maybe . Picture of car with door open light lit on the instrument cluster ? When does it come on , when driving or sitting still or both ?

You mite want to take it to a qualified repair shop and have it checked for DTC'S - diagnostic trouble codes .
DTC B2555 05: Passenger Compartment Lamp Control Circuit Short to Battery or Open
The body control module (BCM) applies battery voltage to the courtesy lamps through the courtesy lamps high control circuit. When any door is opened, the door ajar switch contacts close and the BCM receives a door-open input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamp high control circuit, providing battery voltage to all of the dome lamps, reading lamps, rear compartment lamp, and vanity mirror lamps. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp high control circuit to prevent a total battery discharge condition.

Do you know how to do basic automotive electrical testing ? How to test inputs and outputs of a control module ? in this case the BCM - body control module ? Find wiring diagrams at
http://www.bbbind.com/free_tsb.html also watch this video ECM Inputs and Outputs Diagnosis

there are at least 3; 1 is using the dash light switch-turn all the way up;2 that show 4 lights on it-push it and it will turn them off-push it again and it will turn them on; three push on one end or the other end of the actual light.

courtesy lights have a 3 position switch 1 is for doors open --on /off 2 is for light off permanent and 3 is for light on in car permanent for reading etc. Other than that check the door switches for a permanent earth fault.

Does the van have remote keyless entry (RKE) system ?
Interior Lighting System Description
Vehicles with the optional remote keyless entry (RKE) system have interior lighting controlled by the body control module (BCM).
This vehicle uses a delayed interior lighting system.
The system functions as follows:
• The dome lamps will illuminate when any door is opened.
• The dome lamps will remain on for 20 seconds after the last door is closed.
• The delay is canceled and the dome lamps will go out when the ignition switch is turned to the ON position.
• The illuminated entry function will not operate when the dome lamp defeat switch is in the OFF position.
• The interior lighting system is protected from battery rundown by the retained accessory power (RAP) system. The RAP system functions by shutting down interior lights after 10 minutes (when ignition is OFF).

Interior Lights Circuit Description
When the interior lamps circuits are closed/enabled, the courtesy lamp relay is activated by the two following coil circuits:
• CKT 690 (GRY/BLK) which is the courtesy lamp enable output of the body control module (BCM) driving the coil side of the relay.
• CKT 1732 (ORN) which is the coil output side of the relay going to the potential grounding switches/sources.
When the courtesy lamp relay is enabled, CKT 156 (WHT) (courtesy lamp output) is enabled by the closed contact at the relay and then grounded by CKT 750 (BLK) at G110.
Some of these circuits can also be activated with the headlamp and panel dimmer switch. When this happens, the coil output side of the inadvertent power relay is grounded to the body control module (BCM) via CKT 1393 (DK BLU)
CKT 40 (ORN) from the courtesy fuse drives both input sides of the inadvertent power relay. When the contact is pulled closed, CKT 1732 (ORN) is supplied power, thus driving any lamps/circuits attached that circuit and providing ground.
The body control module (BCM) also monitors the following four door inputs:
• CKT 49 (DK BLU) -- LH door jamb switch input
• CKT 54 (ORN) -- RH door jamb switch input
• CKT 775 (PNK) -- Side door jamb switch input
• CKT 656 (YEL) -- Rear door jamb switch input/liftgate strut switch input (depending on option content)
When the doors are closed, the body control module (BCM) is in a floating state of 0-2 volts. When the doors are opened, the courtesy lamp relay is activated, sending power to the courtesy lamps.
The headlamp and panel dimmer switch also activates the following interior courtesy lamps when the switch is placed in the PARK or HEADLAMP ON positions:
• RF power window switch
• RH power door lock switch
• LH power window switch
• LH power door lock switch
• LH outside rearview mirror control switch
• Rear radio control head
The dome lamps can be disabled by closing the dome lamp defeat switch located on the headlamp and panel dimmer switch.

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Courtesy or Dome Lamps Inoperative
Step
Action
Value(s)
Yes
No
Important: Verify functional bulbs before beginning diagnostic procedure.
1
Did you perform the Lighting Diagnostic System Check?
--
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Are all of the courtesy/dome lamps inoperative?
--
YES - Go to Step 6
NO - Go to Step 3
3
Activate courtesy/dome lamps
With DMM, check for battery voltage from inoperative lamp CKT 1732 (ORN) to ground
Is battery voltage present?
B+
YES - Go to Step 4
NO - Go to Step 5
4
Repair open in CKT 156 (WHT) between inoperative lamp assemply and S214.
Is the repair complete?
--
NO - Go to Step 10
--
5
Repair open in CKT 1732 (ORN) between inoperative lamp assemply and one of the following splices:
• S258
• S301
Is the repair complete?
--
Go to Step 10
--
6
Turn the courtesy lamp switch to the ON position
Check for battery voltage at BCM C2 cavity B12.
Is battery voltage present?
B+
Go to Step 7
Go to Diagnostic System Check - Body Control System in Body Control Systems
7
Verify continuity of the following three circuits with DMM:
• CKT 1732 (ORN) between courtesy lamp relay and body control module
• CKT 156 (WHT) between courtesy lamp relay and S214
• CKT 750 (BLK) between courtesy lamp relay and S206
Are all of the circuits functional?
--
Go to Step 8
Go to Step 9
8
Replace courtesy lamp relay.
Is repair complete?
--
Go to Step 10
--
9
Repair the inoperative circuit.
Is the repair complete?
--
Go to Step 10
--
10
Operate the system in order to verify the repair.
Did you correct the condition?
--
System OK
Go to Step 2

The little switch that gets pushed in when door closes is faulty. Once this is replaced you should have no further problems.

Been having a problem with the dome lights on a 99 chevy blazer. Still can't figure out what the problem is. There is a dome light overide button located under the dimmer wheel. When I push the overide button in the dome light goes off, but when I open any of the doors the dome light will not come on. When the overide button is out the dome light stays on all the time and will not turn off even though every door is closed. I checked all the pushbuttons and everything tests good. Has anyone had this problem and know how to fix it?

Why didn't you hook into the entertainment system (radio ) ?
The one that turns on when the door opens is controlled by the BCM -body control module .You probably shorted out the transistor in side the BCM .
These lamps may be manually turned on by placing the interior lamp switch in the ON position, or by opening a door.
• The Dome Lamp
• The Rear Compartment Courtesy Lamp
• The Rear View Mirror Map Lights
The inadvertent power control circuit of the BCM supplies battery positive voltage to the dome lamp and the map lamps. When any door is opened, the door jamb switch contacts close providing a door open input to the BCM. The BCM then provides a ground to the interior lamps. The interior lamps receive a ground at G401 or G403.
If the driver inadvertently leaves any interior lamp on the BCM will turn it off after a 20 minute time-out.
The courtesy lamps will normally turn off using the theater dimming feature. The BCM provides a pulse width modulated ground to the interior lamps for the theater dimming feature. The courtesy lamps will also turn off immediately if a door lock command is received with all the doors closed, or if the ignition switch is turned to the ON position.

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Dome Lamps Inoperative
ematic Reference: Interior Lights Schematics
DEFINITION: Only the dome lamp is inoperative.
1
Did you perform the Diagnostic System Check - Vehicle?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Vehicle
2
Place the instrument panel (I/P) dimmer switch in the DOME position.
Does the dome lamp illuminate?
YES - Go to Testing for Intermittent Conditions and Poor Connections
NO - Go to Step 3
3
Disconnect the dome lamp assembly.
Probe the courtesy lamp supply voltage circuit with a test lamp that is connected to a good ground.
Does the test lamp illuminate?
YES - Go to Step 4
NO - Go to Step 6
4
Connect the test lamp between the courtesy lamp supply voltage circuit and the courtesy lamp low control circuit.
Does the test lamp illuminate?
YES - Go to Step 5
NO - Go to Step 7
5
Inspect for poor connections at the harness connector of the dome lamp assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
YES - Go to Step 9
NO - Go to Step 8
6
Repair an open, high resistance, or short to ground in the courtesy lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .
YES - Did you complete the repair?
NO - Go to Step 9
--
7
Repair an open or high resistance in the courtesy lamp low control circuit. Refer to Circuit Testing and Wiring Repairs .
YES - Did you complete the repair?
NO - Go to Step 9
--
8
Replace the dome lamp assembly. Refer to Dome Lamp Replacement .
YES - Did you complete the replacement?
NO - Go to Step 9
--
9
Operate the system in order to verify the repair.
Did you correct the condition?
YES - System OK
NO - Go to Step 3

Turn the headlight switch anti clockwise until you hear a click

There is a feature to disable the interior lights when the doors are open for camping. (Turn the switch fully clockwise).

You will need to test the Body Control Module, it controls the lights.