383 Mag stroker won't turn off

emunns

emunns

Member
Nov 5, 2015
53
Seattle
Boat Info
'07 Sea Ray 240 Sundeck
Engines
383 MAG Stroker w/Bravo III
We have '07 240 Sun Deck that we re-powered two years ago with new 383 Mag Stroker installed by the dealer. The motor now has 170 hours and has run flawless up until yesterday when I turned the key "off" and the motor kept running. The radio turned off like normal but the Smart craft gauges stayed on. I turned the key on and off several times and nothing. I flipped the "kill" switch and nothing. After maybe 15mins the motor somehow turned itself off. We were at the fuel dock and our slip is 100 yards away. After 15 mins of poking around I started it up like normal and we moved to our slip. Again turned the key "off" and nothing. Turned the key on-off several times and nothing except a Smart craft alarm "<WARNING HORN> <WARNING HORN IN BOAT IS NOT OPERATING. THERE WILL BE NO AUDIBLE ALARM IN CASE OF ENGINE MALFUNCTION.". The motor again turned itself off after awhile.

Turning the key to the left turns the radio on. Turning the key to the right gives me a single warning beep and turns the gauges on. Turning the key and removing it and the gauges stay on until I turn the batteries off.

On my list to check out is the purple wire from the alternator and the ECM relay.

Thoughts? Thanks for you help.
 
** Update

Some how the computer relay failed. A $40 replacement from SeaRay and all is well again. I'm not sure what caused this problem and that is still bugging me but everything is running and turning off just as it should.
 
This issue just happened again . Turned key off and gauges and motor stayed on. Went back to the motor and tapped on the relay a couple times and “click”, everything turned off.
I replaced the alternator almost two months ago. It’s putting out 13.8-14.1 volts while running. This is more than I remember the old alternator making but seems appropriate. Could this be causing the issue? Over loading the relay?
 
This is the relay in question.

also to note, I pulled this relay and the motor would still fire up, run and turn off. Voltage on the Smartcraft gauge was fluctuating between 11.8v-14.2v so I only ran it for a couple seconds.
 

Attachments

  • IMG_6963.jpeg
    IMG_6963.jpeg
    128.3 KB · Views: 50
IMO, it is unlikely that the new relay is the problem, if the circuit is properly load protected.
Getting the relay to open by lightly tapping it could indicate it is receiving enough of a signal (voltage) to keep it closed.
I would check pin 86 at that relay for voltage after the ignition is switched off? There may be something else in the ignition circuit allowing enough residual voltage to cause your problem.
Edit: Sorry, missed your last post. Did your last alternator fail with high voltage?
 
Thornton69 said:
IMO, it is unlikely that the new relay is the problem, if the circuit is properly load protected.
Getting the relay to open by lightly tapping it could indicate it is receiving enough of a signal (voltage) to keep it closed.
I would check pin 86 at that relay for voltage after the ignition is switched off? There may be something else in the ignition circuit allowing enough residual voltage to cause your problem.
Edit: Sorry, missed your last post. Did your last alternator fail with high voltage?
Click to expand...

The last alternator only had ~160 hours on it. With motor running it was only making 11.8-12.1 volts. I figured it was just a crap alternator from the factory. I've never had one die so quickly.

I'll check voltage at the ignition switch (key) and at pin 86 on the relay. It does sound like the circuit could have some residual power in it keeping the relay closed and that really confuses me. I bought a new key ignition and I'll replace that, because why not. It's 16 years old and maybe causing this. I have another new alternator I can swap in also, just to rule that out as well.

This is such a weird problem with a motor that only has 170 hours on it. Thanks for your help and suggestions.
 
You must log in or register to reply here.

Forum statistics

Threads
113,188
Messages
1,428,234
Members
61,099
Latest member
Lorenzo512
Back
Top