Just put in a replacement right taillight in my sister's 1991 760 Turbo. We were checking to make sure everything works (brake, backup, turn signal, flashers, etc). No matter what we tried, nothing seemed to make the very top bulb on each side work......Anyone know what these are supposed to be for?

Thanks. Dan

 

Those are your fog lights.
The one on the left is the only one that should work and have a bulb.
There's a toggle switch by the light switch that turns it on.
Ed