Pinpoint Test C: A Map Reading Lamp Is Inoperative

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

C1 CHECK POWER TO THE FRONT INTERIOR LAMP

Position the front interior lamp switch in the ON position.
Does the front interior lamp operate?

Yes

CHECK the condition of the bulb. If the bulb is blown INSTALL a new bulb. If the bulb is OK INSTALL a new front interior lamp. TEST the system for normal operation.

GO to C2.

C2 CHECK THE GROUND TO THE FRONT INTERIOR LAMP

Disconnect: Front Interior Lamp C918b (except wagon) or C489b (wagon only).
Measure the resistance between the front interior lamp C918b pin 2, circuit 31-LC7 (BK), or C489b pin 2, circuit 31 -LB6 (BK), harness side and ground.

Fig 1: Checking The Ground To The Front Interior Lamp
Courtesy of FORD MOTOR CO.
Is the resistance less than 5 ohms?

Yes

INSTALL a new front interior lamp. TEST the system for normal operation.

REPAIR circuit 31-LC7 (BK) or 31-LB6 (BK). TEST the system for normal operation.