Pinpoint Test A: No Power In All Ignition Switch Positions
WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 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 IGNITION SWITCH in this service information. 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 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 MULTIFUNCTION ELECTRONIC MODULES -- FUSION, MILAN & MKZ article. 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.