As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHX - LANDING GEAR - FLT 0644 - DURING CRUISE CREW REPORTED THE LT MLG RED LIGHT ILLUMINATED IN CRUISE WITH NO NOISE OR BUFFET. CREW CYCLED THE GEAR HANDLE TO UP AND BACK TO OFF. LIGHT WAS INTERMITTENT REMAINDER OF FLT. MAINTENANCE PERFORMED A GENERAL VISUAL INSPECTION OF THE UPLOCK SWITCH AND OPERATIONALLY TESTED IAW BOEING 737-300 MM 32-61-21-4. REMOVED AND REPLACED THE MAIN GEAR RED LIGHT CARD M986 IAW MM 32-9-20-4. NO FAULTS WERE NOTED.