As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A/C ARRIVED WITH APU GENERATOR INOP ON MCO. DURING TROUB LESHOOTING, WE FOUND TH APU GEN FIREWALL PLUG HAD A L OOSE CONTACT PIN . HARNESS WAS REMOVED AND PLUG WAS OPENED TO DISCOVER A MELTED CONNECTOR AND SHIELDING . HARNESS ASSEMBLY IS TO BE REPLACED ON AEROMEXICO NON ROUTINE CARD. PART # OF HARNESS IS7939409-501