Pinpoint Test F: A Single Illumination Source Is Inoperative

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Cluster and Panel Illumination for schematic and connector information.

Normal Operation

The lighting control module (LCM) supplies a variable pulse width modulated (PWM) voltage to the dimmable illumination sources through circuit 484 (OG/BK). The dimmable illumination sources are grounded through circuit 57 (BK) and 676 (PK/OG). With the ignition switch in the ACCESSORY or RUN positions, voltage is supplied from the central junction box (CJB) to the door lock control switches and heated seat control switches through circuit 964 (DB/LG). The door lock control switches and heated seat control switches are grounded through circuit 57 (BK).

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Headlamp switch
Adjustable pedal switch
Traction control switch
Message center switch
Overhead console (without moonroof)
Heated rear window switch
Driver door lock control switch
Passenger door lock control switch
Floor shifter (if equipped)
Driver heated seat control switch
Passenger heated seat control switch
DDM

PINPOINT TEST F: A SINGLE ILLUMINATION SOURCE IS INOPERATIVE

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

F1 CHECK FOR VOLTAGE TO THE INOPERATIVE LAMP(S)

Key in OFF position.
Disconnect: Inoperative Illumination Source
Key in ON position.
With the parking lamps on, rotate the instrument panel dimmer switch to the maximum brightness position.

Measure the voltage between the inoperative illumination source and ground as follows:

Inoperative Illumination Source	Connector-Pin	Circuit
Headlamp switch	C205a-2	484 (OG/BK)
Adjustable pedal switch	C2089-5	484 (OG/BK)
Traction control switch	C280-3	484 (OG/BK)
Message center switch	C253-7	484 (OG/BK)
Overhead console (without moonroof)	C930-4	484 (OG/BK)
Heated rear window switch	C241-3	484 (OG/BK)
Driver door lock control switch	C505-1	964 (DB/LG)
Passenger door lock control switch	C605-1	964 (DB/LG)
Driver heated seat control switch	C538-5	964 (DB/LG)
Passenger heated seat control switch	C630-5	964 (DB/LG)
Floor shifter	C3247-2	484 (OG/BK)

Is the voltage greater than 10 volts?

YES : Go to F2.
NO : For the door lock control switches and heated seat control switches, VERIFY that the CJB fuse 9 (7.5A) is OK. If OK, REPAIR the circuit in question. TEST the system for normal operation.
For all others, REPAIR the circuit in question. TEST the system for normal operation.

F2 CHECK CIRCUITS 57 (BK) AND 676 (PK/OG) FOR AN OPEN

Key in OFF position.

Measure the resistance between inoperative illumination source and ground as follows:

Inoperative Illumination Source	Connector-Pin	Circuit
Headlamp switch	C205a-1	57 (BK)
Adjustable pedal switch	C2089-4	57 (BK)
Traction control switch	C280-7	57 (BK)
Message center switch	C253-2	57 (BK)
Overhead console (without moonroof)	C930-9 C930-2	57 (BK) 676 (PK/OG)
Heated rear window switch	C241-7	57 (BK)
Driver door lock control switch	C505-7	57 (BK)
Passenger door lock control switch	C605-7	57 (BK)
Driver heated seat control switch	C538-1	57 (BK)
Passenger heated seat control switch	C630-1	57 (BK)
Floor shifter	C3247-4	57 (BK)

Is the resistance less than 5 ohms?

YES : INSTALL a new switch or component in question. TEST the system for normal operation.
NO : REPAIR the circuit. TEST the system for normal operation.