Service difficulty report · Relay · Beech B300C

Difficulty date
January 18, 2021
Submitted
January 18, 2021
Operation
General aviation
Aircraft
N517K
Make and model
Beech B300C
Aircraft serial
FM65
Aircraft time
714 hours, 635 cycles
Part
Relay
Part number
M57571021
Condition
Failed
Location
Fuel Panel
Part time
714 hours, 635 cycles
Component
Fuel Panel · Beech
Component part number
M57571021
Stage of operation
TX
How discovered
O
Nature of condition
H, W
Precautionary procedure
H

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

FUEL SYSTEM INDICATION FOR MAIN/AUX/ER GOES THRU K1 RELAY PN M5757/1-021 BEHIND FUEL PANEL. NEW RELAY SAME PART NUMBER ARE BEING SOLD WITH AN INCORRECT DRAWING OF CONTACTS, POSSIBLY INTERNALLY MISWIRED OR BOTH. UPON INSTALLING NEW CIRCUIT BREAKERS IMMEDIATELY POPPED. THINKING THE TECHNICIAN MADE A MISTAKE WE REPLACED IT WITH THE SAME RESULT WIRED BY THE MANUFACTURERS WIRING DIAGRAMS. THE NEW RELAY WAS INSTALLED AND PAYING EXTREME ATTENTION TO WIRING WAS WIRED, PER BEECH DRAWINGS. SYSTEM DID NOT FUNCTIONS ONCE AGAIN. AFTER CLOSE EXAMINATION THE DIAGRAM ON THE BACK OF THE RELAY SHOWED A DISTINCT DIFFERENCE MAKING THE MASTER PIN CONNECT TO THE WRONG POINT (CORRECT WAS X1 FOR BLUE MARKER, NEW RELAY HAS POINT X2) COMPLETELY OPPOSITE THEREBY RENDERING THE SYSTEM INOPERABLE.

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