Pinpoint Test P: The Fog Lamps Are Inoperative

P1 CHECK THE LOW BEAM HEADLAMP OPERATION
- Key in ON position.
- Place the headlamp switch in the headlamps ON position.
- Do the headlamps illuminate?
- Yes : GO to P2.
- No : REFER to HEADLAMPS to continue diagnosis of the headlamps.
P2 CHECK THE FOG LAMP INDICATOR LAMP
- Engage the fog lamp switch.
- Is the front fog lamp indicator lamp illuminated?
- Yes : LEAVE the fog lamp switch engaged. GO to P5.
- No : GO to P3.
P3 CHECK CIRCUIT 15-LD16 (GN/RD) FOR VOLTAGE
- Key in OFF position.
- Disconnect: Headlamp Switch C205.
- Key in ON position.
- Measure the voltage between the headlamp switch C205-7, circuit 15-LD16 (GN/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Headlamp Switch C205-7, Circuit 15-LD16 (GN/RD), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH . TEST the system for normal operation.
- No : GO to P4.
P4 CHECK CIRCUIT 15-LD16 (GN/RD) FOR AN OPEN
- Key in OFF position.
- Disconnect: CJB C270f.
- Measure the resistance between the headlamp switch C205-7, circuit 15-LD16 (GN/RD), harness side and the CJB C270f-4, circuit 15-LD16 (GN/RD), harness side.
  
  Fig 2: Checking Circuit 15-LD16 (GN/RD) For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : REPAIR or INSTALL a new CJB. TEST the system for normal operation.
- No : REPAIR the circuit. TEST the system for normal operation.
P5 CHECK CIRCUIT 15S-LD16 (GN/RD) FOR AN OPEN
- Key in OFF position.
- Disconnect: Fog Lamp Relay C1007.
- Key in ON position.
- Measure the voltage between the fog lamp relay C1007-3, circuit 15S-LD9 (GN/BK), harness side and ground.
  
  Fig 3: Checking Relay Power Supply
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to P7.
- No : GO to P6 .
P6 CHECK THE HEADLAMP SWITCH
- Key in OFF position.
- Connect a fused (20A) jumper wire between the headlamp switch C205-7, circuit 15S-LD16 (GN/RD), harness side and the headlamp switch C205-3, circuit 15S-LD9 (GN/BK), harness side.
  
  Fig 4: Checking Headlamp Switch
  Courtesy of FORD MOTOR CO.
- Key in ON position.
- Measure the voltage between the fog lamp relay C1007-3, circuit 15S-LD9 (GN/BK), harness side and ground.
  
  Fig 5: Checking Relay Power Supply
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH . TEST the system for normal operation.
- No : REPAIR the circuit. TEST the system for normal operation.
P7 CHECK CIRCUIT 15S-LD19 (GN/BU) FOR AN OPEN
- Measure the voltage between the fog lamp relay C1007-1, circuit 15S-LD19 (GN/BU), harness side and ground.
  
  Fig 6: Measuring Voltage Between Fog Lamp Relay C1007-1, Circuit 15S-LD19 (GN/BU), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to P8.
- No : REPAIR or INSTALL a new BJB. TEST the system for normal operation.
P8 CHECK CIRCUIT 91-DA 3 (BK/OG) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the fog lamp relay C1007-2, circuit 91-DA3 (BK/OG), harness side and ground.
  
  Fig 7: Measuring Resistance Between Fog Lamp Relay C1007-2, Circuit 91-DA3 (BK/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to P9.
- No : REPAIR the circuit. TEST the system for normal operation.
P9 CHECK THE FOG LAMP RELAY
- Carry out the fog lamp relay component test. Refer to COMPONENT TESTING for component testing.
- Is the fog lamp relay OK?
- Yes : REPAIR circuit 15S-LD1 (GN/YE). TEST the system for normal operation.
- No : INSTALL a new fog lamp relay. TEST the system for normal operation.