Pinpoint Test A: No Power In All Ignition Switch Positions
WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.
NOTE:
Verify that battery voltage is 10 volts or greater.
- A1 CHECK AT THE IGNITION SWITCH FOR VOLTAGE
- Ignition OFF.
- Disconnect: Ignition Switch C250.
- Measure the voltage between ignition switch C250-4, circuit SBP27 (BU/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- Yes: INSTALL a new ignition switch. REFER to Removal and Installation . TEST the system for normal operation.
- No: VERIFY SJB fuse 27 (20A) is OK. If OK, GO to A2. If not OK, REFER to the appropriate SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short. TEST the system for normal operation.
- A2 CHECK THE IGNITION SWITCH INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: SJB C2280A.
- Measure the resistance between ignition switch C250-4, circuit SBP27 (BU/RD), harness side and SJB C2280A-14, circuit SBP27 (BU/RD), harness side.
- Is the resistance less than 5 ohms?
- Yes: GO to A3.
- No: REPAIR circuit SBP27 (BU/RD). TEST the system for normal operation.
- A3 CHECK FOR CORRECT SJB OPERATION
- Disconnect: All SJB connectors.
- Check the SJB connectors for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: All SJB connectors and make sure the connectors seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new SJB. REFER to INSTALLATION . TEST the system for normal operation.
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.