As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK. ATC TRANSPONDER INOP. GROUND SAFETY RELAY LIGHT ON IN FLIGHT COULD NOT PRESSURIZE PAST 1.8 PSID. LOW SPEED BRAKE RELEASE LIGHT ILLUMINATED. RESET C/B BOTH TRANSPONDERS RERACKED, GROUND OPS CHECKED OK. SWAPPED RELAY BETWEEN R952 AND K3. FOUND R226 RELAY WAS INSTALLED INCORRECTLY. REINSTALLED BACK IN THE CORRECT POSITION. GROUND SAFETY RELAY TEST OK.