Logo
FULL SITE MENU

5.7l Black Scorpion intermittent starting

0

06 Enzo SV230

New member
I have a 2006 centurion Enzo with the 5.7l black scorpion. Bought last week. Test drive went great, get it home and have intermittent starting issues immediately. Starter seemed to have a dead spot, put in a new starter, no change. Put in new slave relay, no change. Removed engine ground, cleaned everything up and put back together, no change. I seem to be getting correct voltage readings everywhere I check. What’s next? Is the new MercCruiser starter bad? I feel like I’m chasing ghosts.
 
Welcome
If you mean where you turn the key and the motor doesn't crank, than it's most likely the neutral safety switch in the throttle control. Turn key to start and move the throttle forward or reverse slightly, it should crank up
 
Changed the ignition switch, seems to help some, but not fix the problem completely. Or maybe dumb luck it seems a little better…
I have tried messing with the throttle, and didn’t seem to be the issue. I will pull the neutral safety switch and do some testing.
 
Had a used to be Merc machanic take a look. His thought is a corroded or bad wire from the dash to the engine bay. He said to grab a multimeter and start testing each one. Tedious, but easy… I will keep the group updated on what I find.
There is full voltage on one side of the slave, other large post seems right(powers when you start). One thing my friend is stuck on is there is ALWAYS 12v to both of the small posts on the slave. Is that correct? He doesn’t seem to think so.
 
One thing my friend is stuck on is there is ALWAYS 12v to both of the small posts on the slave. Is that correct? He doesn’t seem to think so.
Click to expand...
May have found the issue
1. Does your boat have a transmission?

With the Black Scorpion MX this can be correct. Normally the neutral safety switch is in the throttle handle, but the Scorpion has a switch in the trans. So instead of one side of the slave relay being always grounded, the ground is applied to energize the relay. So 12V is always applied to the relay and instead of the small wire being Yel/Red it will be Red/Pur.

1784118099763.png


Item 7 is the neutral safety switch
Look at the switch and the connector
 
with the key=START and the Neutral safety switch=OPEN, seeing +12VDC on both small posts is 'normal'.

Pretty sure +12VDC comes from the key switch, in START, via the RED/YEL wire, and GROUND is provided, thru the YEL/BLK wire, when the Neutral safety switch is closed (in Neutral).
 
post #8 has a different wiring diagram than shown in post #6...

either way, with the key = START, if there is no voltage drop across the slave solenoid's coil, then the ground connection is at fault - whether its a wire or a bad connection...
 
Back
Top