Pinpoint Test B: An Individual Courtesy Lamp Is Inoperative

WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

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

NOTE: Make sure the interior lamp switches are in the DOOR position.

B1 CHECK CIRCUIT VLN33 (GY/VT) FOR AN OPEN

Disconnect: Suspect Courtesy Lamp
Key in ON position.
Open the driver door.

Measure the voltage between the suspect courtesy lamp, harness side and ground as follows:

Location	Connector-Pin	Circuit
Cargo lamp	C926a-3	VLN33 (GY/VT)
Front courtesy lamp	C918-1	VLN33 (GY/VT)
Courtesy/map lamp	C931-3	VLN33 (GY/VT)

Is the voltage greater than 10 volts?

YES : Go to B2.
NO : REPAIR the circuit. TEST the system for normal operation.

B2 CHECK CIRCUIT GD182 (BK/GY) FOR AN OPEN

NOTE: The battery ground cable must be disconnected to obtain accurate test results.

Disconnect the battery. Refer to BATTERY, MOUNTING AND CABLES article.

Measure the resistance between the suspect demand lamp, harness side and ground as follows:

Location	Connector-Pin	Circuit
Cargo lamp	C926b-1	GD182 (BK/GY)
Front courtesy lamp	C918-2	GD182 (BK/GY)
Courtesy/map lamp	C931-1	GD182 (BK/GY)

Is the resistance less than 5 ohms?

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