As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU LIGHT ILLUMINATED ON T/O. PULLED HANDLE, LIGHT CONTINUED TO ILLUMINATE ON TAXI BACK. REJECTED TAKEOFF. REPLACED APU TAILPIPE OVERHEAT DET CONNECTOR D1878 AND WIRE W765-451-18R DUE TO HIGH RESISTANCE SHORT. OPS TEST AND RUN TEST CHECK GOOD. CONNECTOR (P/N 878581-01).