As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITHIN 5 MINUTES OF SWITCHING OVER TO NR 2 ENGINE BLEED FOR NR 1 PACK LOWER AFT BODY OVERHEAT LIGHT CAME ON. LIGHT EXTINGUISHED WITHIN 30 SECONDS OF PLACING NR 2 BLEED SWITCH BACK OFF. RAN NR 1 AND NR 2 ENGINES TO POWER. COULD NOT DUPLICATE PROBLEM. LEAK CHECKED ALL DUCTS AND CLAMPS UNDER GIVEN CONDITIONS. NO LEAKS FOUND.