Engine computer 50-amp breaker wired incorrectly - both wires on same circuit

[FTL_Alan]

2008 350 SS, 496 Mag HOs.. My mechanic was out this week to replace hoses and check to make sure that the trim pump solenoids I replaced my self were wired correctly. I found this comment on the invoice:

"MAIN 50 AMP BREAKER (on the engine, for the computer) WIRED INCORRECTLY. BOTH WIRES WERE ON SAME CIRCUIT. COULD OF CAUSED DAMAGE TO ELECTRICAL SYSTEM IF LEFT THIS WAY."

I have a call into him to get more info. Does anyone have any idea what this is about? I've used the same mechanic since buying the boat in 2015. In 2016, they did take out both engines in order to replace transom assemblies. While engines were out, I had them replace manifolds and risers. I assume this issue happened when they re-installed the engines but I have no idea. The boat's been running fine since the engines were re-installed.

 

[AllDodge]

Assuming your not the original owner, this was probably done when the PO had issues and someone put both connections together on the same terminal. The breaker may be defective but in most cases its good, but was bypassed trying to find another issue.

To verify, have battery switch ON then measure the voltage on both sides of the breaker. No need to get the wires correct before doing this. If you get bat voltage on both sides, then the wires just need to be reinstalled

 

[FTL_Alan]

Thanks AllDodge, appreciate the quick response. Just talked to mechanic, he said its the breaker on the starboard engine that provides protection for the electrical harness and engine computer. He said the correct wiring is one wire in and one wire out. Mine had two wires in. He said that would have compromised the circuit protection of the breaker, which means that the harness and computer would have no protection in the event of an electrical issue. He didn't speculate when the problem occurred. As you noted, it could have been done by either the original owner or the 2nd. I am the third. I assumed when my my mechanic removed the engines and reinstalled, that this would have been discovered. Maybe not, I have no idea.

 

[AllDodge]

He said the correct wiring is one wire in and one wire out. Mine had two wires in.

Agree, without the breaker inline, then if there is a short there will be problems. Push the button, then measure the voltage on each of the 2 terminals. If both have 12V then the breaker is passing voltage and all that needs to be done is move one of the wires over to the other unused terminal. If there is no voltage on other terminal, replace the breaker