This happened to me shortly after I got my Roadster. The PCB was replaced under warrantee (fortunately). A short-term fix was just to remove the bulb. To avoid the cost of a new PCB you could jury-rig an independent power supply with a switch under the dash. You don't have to use the rear fog light very much, after all.
Last edited by Felix42; 01/04/16 10:15 AM.