Service difficulty report · Contactor · Cessna 172M

Difficulty date
July 22, 2005
Submitted
December 2, 2005
Operation
General aviation
Make and model
Cessna 172M
Aircraft time
6,840 hours
Engine
Lyc O320E2D
Part
Contactor
Part number
111138D
Condition
Seized
Location
Starter
Component
Engine Starter
Stage of operation
CL
How discovered
O
Nature of condition
B
Precautionary procedure
A

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

What was found

(CAN) RECURRING DEFECT, STARTER CONTACTOR COILS FUSED TOGETHER DUE TO EXCESSIVE HEAT WHICH RESULTED IN STARTER GETTING STUCK (ON). AFTER 9 ATTEMPTS, AFTER BEING MISLED BY MFG THAT THEY HAD FAULTY CONTACTORS, FOUND MAIN POWER WIRE FROM CONTACTOR TO STARTER HAD CORRODED TERMINALS WHERE CRIMPED TO WIRE. THIS WAS NOT VISIBLE UNTIL CUT OPEN. THE CORROSION LED TO A HIGHER CURRENT DRAW THAN NORMAL PASSING ACROSS THE CONTACTOR WHICH MELTED THE COIL WIRED IN THE CONTACTOR.

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