Pinpoint Test A: The Control Illumination Is Inoperative
- A1 CHECK THE PARKING LAMPS
- Key in OFF position.
- Place the headlamp switch in the ON position.
- Are the exterior lamps on?
- A2 CHECK CIRCUIT 14 (BN) FOR VOLTAGE
- Place the headlamp switch in the OFF position.
- Disconnect: Headlamp Switch C205b.
- Place the headlamp switch in the ON position.
- Measure the voltage between the headlamp switch C205b pin 6, circuit 14 (BN), harness side and ground.
Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes
: GO to A4.
- No
: GO to A3.
- A3 CHECK CIRCUIT 14 (BN) FOR AN OPEN OR A SHORT TO GROUND
- Place the headlamp switch in the OFF position.
- Disconnect: Headlamp Switch C205a.
- Measure the resistance between the headlamp switch C205a pin 12, circuit 14 (BN), harness side and the headlamp switch C205b pin 6, circuit 14 (BN), harness side; and between the headlamp switch C205a pin 12, circuit 14 (BN), harness side and ground.
Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the headlamp switch connectors, and greater than 10,000 ohms between the headlamp switch and ground?
- Yes
: INSTALL a new headlamp switch. REFER to EXTERIOR LIGHTING
. TEST the system for normal operation.
- No
: REPAIR the circuit. TEST the system for normal operation.
- A4 CHECK CIRCUIT 19 (LB/RD) FOR AN OPEN OR A SHORT TO GROUND
- Disconnect: Audio Unit C290a.
- Place the headlamp switch in the OFF position.
- Measure the resistance between the headlamp switch C205b pin 1, circuit 19 (LB/RD), harness side and the audio unit C290a pin 1, circuit 19 (LB/RD), harness side; and between the headlamp switch C205b pin 1, circuit 19 (LB/RD), harness side and ground.
Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the audio unit and the headlamp switch, and greater than 10,000 ohms between the audio unit and ground?
- Yes
: INSTALL a new headlamp switch. REFER to EXTERIOR LIGHTING
. TEST the system for normal operation.
- No
: REPAIR the circuit. TEST the system for normal operation.