Pinpoint Test U: The Fog Lamps Are On Continuously

WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

U1 CHECK CIRCUIT 478 (TN/OG) FOR SHORT TO BATTERY
- Key in OFF position.
- Disconnect: Fog Lamp Relay.
- Do the fog lamps continue to illuminate?
Yes

REPAIR circuit 478 (TN/OG). TEST the system for normal operation.

No

INSTALL the fog lamp relay. GO to U2.
U2 CHECK THE HEADLAMP SWITCH
- Disconnect: Headlamp Switch C205a.
- Do the fog lamps continue to illuminate?
Yes

GO to U3.

No

INSTALL a new headlamp switch refer to HEADLAMP SWITCH . TEST the system for normal operation.
U3 CHECK THE FOG LAMP RELAY
- Carry out the fog lamp relay component test.
  Refer to COMPONENT TESTING for schematic and connector information.
- Is the fog lamp relay OK?
Yes

REPAIR circuit 477 (LB/BK). TEST the system for normal operation.

No

INSTALL a new fog lamp relay. TEST the system for normal operation.