Hi. My buddy just purchased a 1999 F-150. He called me to complain that the white lights on either side of the high mount stoplight (above the rear cab window) won't turn off. Are these a bed light or a reverse light? If they are independent of the reverse lights, how do you turn them off? Thanks.

 

I have the same truck. Here is the operation information. That is the cargo light

The GEM and the CTM illuminate the interior lamps when any door is open or ajar. The interior lamps are the interior lamp, the cargo lamp and the door courtesy lamp. The courtesy lamps will shut off when:
The doors are closed and the illuminated entry (GEM only) feature is not active.
The vehicle speed is greater than 15 mph (24 km/h) . The interior lamps will not be reactivated until the vehicle speed is less than 10 mph (16 km/h) and a new door open warning lamp switch signal is received (GEM only).
The system inputs to the GEM/CTM are as follows:
The door open warning lamp switches. (Grounded when door is ajar; an open circuit when the door is closed.)
The Vehicle Speed Sensor (VSS) input. (Sinusoid Wave: 0.7V-20V , 2.2 Hz/MPH [1.37 Hz/km/h] [GEM only].)
The system output to the GEM/CTM is as follows:
The interior lamp relay coil output. (Grounded when activated; open circuit when deactivated.)
Illuminated Entry (GEM Only)
The GEM illuminates the interior lamps when an unlock signal is received from the Remote Anti-theft Personality (RAP) module. The illuminated entry feature will be canceled when any of the following conditions are met:
25 seconds have elapsed since the illuminated entry feature was activated and the courtesy lamp feature is not activated.
The GEM receives a request from the RAP module (remote transmitter lock button pressed) and the courtesy lamp feature is not activated.
The ignition is in the RUN or START position and the courtesy lamp feature is not activated.
The illuminated entry inputs are:
RAP illuminated entry request. (Grounded pulse of varying length.)
Ignition switch in the RUN position. (Battery voltage on both the RUN and RUN/ACC inputs.)
The illuminated entry outputs are:
Interior lamp relay coil output. (Grounded when activated; an open circuit when deactivated.)

 

1. Make sure the instrument illumination control hasn't turned on the interior and cargo lights.

2. Make sure your "Door Ajar" warning light works properly and that none of your doors are registering as open.