What was found
RED CAUTION LIGHT COMES ON FOR OXYGEN SYSTEM - INTERMITTENT. TROUBLESHOT SYSTEM TO COPILOT'S OXYGEN SYSTEM MICROSWITCH. WHEN COPILOT'S SEAT WAS RAISED , END OF A SCREW PUSHED SWITCH CAUSING SWITCH TO MAKE CONTACT. REMOVED COPILOT'S SEAT, CUT END OF SCREW OFF. CHECKED SWITCH FOR PROPER ADJUSTMENT. CHECKS GOOD. OPERATED SEAT, NO INTERFERENCE WITH SWITCH. RE-INSTALLED SEAT, RED LIGHT OUT.