As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT BLEED FAULT LIGHT ILLUMINATED IN FLIGHT. FOLLOWED QRH AND CLOSED LEFT BLEED VALVE, WITH LEFT BLEED VALVE CLOSED, LEFT BLEED FAULT LIGHT ILLUMINATED FOR ABOUT 3 SECONDS, ROUGHLY EVERY 4 MINUTES. MAINTENANCE REPLACED LEFT PRESSURE BLEED SWITCH. ALL CHECKS GOOD.