I have the exact same problem on the same car! There are actually five (5) small lamps that are attached to the rear of the instrument panel module. I have at least two lamps out since one side of my panel is dark.
I have not done the replacement yet, but looking at my Haynes repair manual, a number of dash parts and panels must be removed to get the instrument panel out. After that, you can remove the lamps from their sockets and put new ones in. I suggest that you replace all of the lamps at the same time since it is no small task to get at the instrument panel!
Mark
Changing dash panel lights 1995 Mercury sable how do I do it
Might be able to get at in from underneath but probably will have to remove the dash cover
The 1996 Mercury Sable the OBD 2 connector is under drivers dash next to kick panel
On a 2002 Mercury Mountaineer : The fuse panel is under the dash , on the drivers side
Just to the right of your headlight switch in the dash is your gauge panel dimmer control . Rotate the wheel up to brighten your dash lights . ( also , if turned all the way up it turns on your interior lights )
In a 2002 Mercury Mountaineer : The passenger compartment fuse panel is directly under the dash on the drivers side
According to the drawing in the 1996 Mercury Sable Owner Guide : The fuse panel is under the dash by the brake pedal Also , the Power Distribution Box ( which is " live " ) is located in the front of the engine compartment , near the battery
Might be able to get at in from underneath but probably will have to remove the dash cover
depends on the year but the fuse panel will be on either side of the dash when you open the front doors. the other location will be under the dash usually on the drivers side under a panel labeled "fuses".
on the dash
under dash on drivers side
In a 2002 Mercury Mountaineer : In the fuse panel below the dash , on the drivers side : ( #24 is a 15 amp fuse for the cigarette lighter and OBD II )