Re: Engine will not shut down!!!
Engine: J225TXESS (1990 225hp)
NOTE: This is a NEW engine to me. Upon purchase this problem existed, but the engine was not worked on for a year and a half and I am not finished restoring the boat and trying to set up the engines.
The black/yellow wire from the M on the ignition switch is properly grounded.
This wire splits to two wires by the time it exits from under the flywheel into two single wire connectors. Testing at this point shows both connetors have a good ground, and they are open when the key switch is turned to the "ON" position. Key switch is good (also tested all connection combinations for continuity to be safe - all check out correct)
I removed the emergency kill switch from the circuit to eliminate any possible problems there.
The port connector goes directly into the power pack.
The starboard connector goes into the power pack through the shift interrupter switch.
Once connected, the single wire connector that comes from the shift interrupter switch and goes into the power pack? NO GROUND. OPEN WIRE.
Thus, you are correct: THIS is why the starboard bank of cylinders does not shut down on the key switch, and is the reason that the engine goes no shut down. This is progress. This shows that the problem I am having has been isolated to the shift interrupter switch (assuming the power pack works, but again, will get to that once this is resolved)
I pulled the shift interrupter switch out of the engine and began diagnosing it.
I pulled back the wiring to expose the diode and gain acces to all the connection points.
Testing the shift interrupter switch shows that it works correctly.
Testing the diode shows that the diode functions correctly as a DIODE.
FIRST QUESTION: What is the purpose of the diode in the shift interrupt circuit? From what I can figure, it allows the shift interrupt switch to ground (and thus kill) the starboard bank of cylinders ONLY and keeps the ground created when the shift interrupt switch is activated from backfeeding through the black/yellow wire into the port side? That makes sense.
If that's the case, it would appear that the diode in my FACTORY WIRING is backwards, and that it's in the wrong position. What would make sense to me (assuming diodes purpose is as listed above) is that the ground from the single wire connector leading to the ignition switch should pass through the shift interrupter circuit to allow shutting down the engine. When the shift intterupter circuit is activated, it should allow ground to the power pack but not FLOW BACKWARDS to the port bank.
As well, it appears that diode is located in the wrong direction. (this is hard to do without a diagram)
This is how I THINK it should go:
From the single connector coming form the key switch, ground should be direct to the power pack. The switch interrupt switch should connect into that line, and run through a black/yellow wire to the shift intterupt switch (the other lead from the switch to ground) The diode should be between the junction of the switch interrupt switch and the key switch ground black/yellow wire. This would allow:
Grounding from the key switch to both cylinder banks.
Grounding form the shift interrupter switch to ONLY the starboard bank.
SECOND QUESTION: What looks like factory wiring harnass would be a backwards diode and have the junction of these two wires in the incorrect location: Could this be a part installed from a different engine, or could this be from a counter rotating engine? I'm curios if this is unheard of or something that, from time to time, just happens. In short? WHy?
THANKS FOR ALL THE INPUT. It's helped me trace my problem and isolate the location.
