On the 91 TQ 20v, the right side rear tail lights are out. The light out signal displays on the dash and the alarm sounds. HOWEVER, THE BRAKE LIGHTS WORK FINE.
We've replaced all lights in the circuit several times with new, bulbs, even OEM bulbs, but no change. I can't find any blown fuse.

Any thoughts would be appreciated?

 

A bad ground or a short perhaps

 

or the usual, a dirty or loose connection