Pinpoint Test E: A Single Illumination Source Is Inoperative

WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

E1 CHECK CIRCUIT 19 (LB/RD) FOR AN OPEN

Key in OFF position.
Disconnect: Inoperative Illumination Source.
Place the headlamp switch in the ON position.
Rotate the instrument panel dimmer switch to the full illumination position.

Measure the voltage between the single illumination source, circuit 19 (LB/RD), harness side and ground as follows:

ILLUMINATION SOURCE - CONNECTOR AND CIRCUIT

Illumination Source	Connector (Pin)	Circuit
Power Sliding Rear Window Switch	C203 (5)	19 (LB/RD)
Message Center Switch	C265 (1)	19 (LB/RD)
Four-Wheel Drive Switch	C284 (4)	19 (LB/RD)
Parking Aid Disable Switch	C2035 (8)	19 (LB/RD)
Adjustable Pedal Switch	C2089 (5)	19 (LB/RD)
Upfitter Switch	C2300 (2)	19 (LB/RD)
Overhead Console	C9013 (4)	19 (LB/RD)

Is the voltage greater than 10 volts?

Yes : GO to E2.
No : REPAIR the circuit. TEST the system for normal operation.

E2 CHECK CIRCUIT 57 (BK) FOR AN OPEN

Place the headlamp switch in the ON position.

Measure the resistance between single illumination source, circuit 57 (BK), harness side and ground as follows:

ILLUMINATION SOURCE - CONNECTOR AND CIRCUIT

Illumination Source	Connector (Pin)	Circuit
Power Sliding Rear Window Switch	C203 (4)	57 (BK)
Message Center Switch	C265 (4)	57 (BK)
Four-Wheel Drive Switch	C284 (1)	57 (BK)
Parking Aid Disable Switch	C2035 (4)	19 (LB/RD)
Adjustable Pedal Switch	C2089 (4)	57 (BK)
Upfitter Switch	C2300 (3)	57 (BK)
Overhead Console	C9013 (9)	57 (BK)

Is the resistance less than 5 ohms?

Yes : INSTALL a new component in question. TEST the system for normal operation.
No : REPAIR the circuit. TEST the system for normal operation.