Pinpoint Test J: The Courtesy Lamps Are Inoperative From The Dimmer Control Switch

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

J1 CHECK THE SJB DIAGNOSTIC TROUBLE CODES (DTCs) FROM BOTH CONTINUOUS AND ON-DEMAND SELF-TESTS
- Use the recorded results from the SJB continuous and on-demand self-test.
- Are any DTCs recorded?
Yes : For DTC B1688, GO to J4.

For DTC B1247, REFER to INSTRUMENT CLUSTER AND PANEL ILLUMINATION to continue diagnosis of the backlighting.

For all other DTCs, REFER to SMART JUNCTION BOX (SJB) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .

No : GO to J2.
J2 CHECK THE DIMMER CONTROL SWITCH
- Key in OFF position.
- Disconnect: Dimmer Control Switch C2065.
- Connect a fused (10A) jumper wire between the dimmer control switch C2065-2, circuit CLN28 (GN/BU), harness side and the dimmer control switch C2065-4, circuit CLN27 (WH/BN), harness side.
  
  Fig 1: Checking Dimmer Control Switch
  Courtesy of FORD MOTOR CO.
- Do the courtesy lamps illuminate?
Yes : INSTALL a new dimmer control switch. REFER to EXTERIOR LIGHTING . TEST the system for normal operation.

No : GO to J3.
J3 CHECK CIRCUIT CLN28 (GN/BU) FOR AN OPEN
- Disconnect: SJB C2280d.
- Measure the resistance between the SJB C2280d-26, circuit CLN28 (GN/BU), harness side and the dimmer control switch C2065-2, circuit CLN28 (GN/BU), harness side.
  
  Fig 2: Checking Circuit CLN28 (GN/BU) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to J6.

No : REPAIR the circuit. TEST the system for normal operation.
J4 CHECK CIRCUIT CLN28 (GN/BU) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: SJB C2280d.
- Disconnect: Dimmer Control Switch C2065.
- Measure the resistance between the SJB C2080d-26, circuit CLN28 (GN/BU), harness side and ground.
  
  Fig 3: Checking Circuit CLN28 (GN/BU) For Short To Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
Yes : GO to J5.

No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
J5 CHECK THE DIMMER CONTROL SWITCH
- Connect: Dimmer Control Switch C2065.
- Measure the resistance between the SJB C2080d-26, circuit CLN28 (GN/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes : GO to J6.

No : INSTALL a new dimmer control switch. REFER to EXTERIOR LIGHTING . CLEAR the DTCs. REPEAT the self-test.
J6 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes : INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC CONTROL MODULES . CLEAR the DTCs. REPEAT the self-test.

No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.