Mercruiser 2006 4.3L Engine Will Not Shut Off

[Ortley]

Engine will not shut off, Emergency Cut Off Switch does not work. We have replaced the TKS Diode (Bulletin # 2006-04) Twice, Replace the ignition switch (old one tested good), removed alternator, had tested and opened by an alternator repair shop (alternator good). Service centers don't have a glue just say bring in. Any suggestions? We are now thinking it may be something with fuel pump? Thanks for any help - Ortley

 

[achris]

Sounds like you have a short somewhere between main power and ignition power. How do you shut it off?

 

[Bt Doctur]

starter solenoid bad, starter solenoid wires/cable touching

 

[alldodge]

Engine will not shut off, Emergency Cut Off Switch does not work. We have replaced the TKS Diode (Bulletin # 2006-04) Twice, Replace the ignition switch (old one tested good), removed alternator, had tested and opened by an alternator repair shop (alternator good). Service centers don't have a glue just say bring in. Any suggestions? We are now thinking it may be something with fuel pump? Thanks for any help - Ortley

:welcome: to iboats

Will the engine shut down if the diode is remove?
Have you measured the resistance FWD/REV of the diode, and if so what was it?
If it keeps shorting the diode out, my guess would be something is pulling more current then the diode can take.

 

[Fun Times]

Try separating the boat wiring harness from the engine wiring harness to help determine where the problem may lie. Boat or engine.

Using a 10 pin cannon plug with an ignition key switch such as the one linked below would be the best ideal for this test but the plug is jumpable.
http://www.hardin-marine.com/p-1322...-pigtail-mercury-plug-instrument-side-12.aspx

http://www.youtube.com/watch?v=NUoXFIo2Ab8
http://forums.iboats.com/forum/engi...rting-mercruiser-on-engine-stand-update/page2

 

[Ortley]

Thank you all. We stop the boat by pulling the diode which is blown. It usually immediately shuts off. Will check the starter solenoid and for shorts this weekend. I appreciate the guidance. Will be back to you.