Engine Electrical Crash

G-Daddy

Petty Officer 2nd Class
Joined
May 3, 2002
Messages
197
First things first - Boat is a 1998 Sportcraft 252 with Mercruiser 350 MAG MPI engine and velvet drive transmission. Engine S/N is 0L03715 and a new short block has about 650 hours on it.

Situation - We launched from Somers Cove Marina on Saturday at 6:30 am and ran up around Smith Island, through Kedges Strait, past the target ship and almost to 66 and the edge of the shipping channel - probably around 22 - 24 miles. Engine speed was at 3200 rpm most of the trip.

Crash - Just as we were at 45 feet of water and preparing to find our spot to begin fishing, the engine and all electrical that runs through the ingition switch shut down with out warning, a miss, or any other indication that anything was wrong. It was just like someone turned the key off. All the other electrical systems on the boat are fine and the battery tested at 12.46v after 5 hours of running only the vhf, gps and occasional use of the sonar. When the engine shut down, the tach still registered 3200 rpm. Thinking that maybe the kill switch was bumped we turned to stop and back to run. When the switch was moved to stop, the tach went to 0. Engine still does not run, but there is 12v to the switch, the engine will crank, but not fire and the third output has 12v when the key is in the on position. No gauges, including oil pressure, voltmeter, engine temp, tach, port and starboard fuel tanks. Everything else that runs through the switch panels works.

Any ideas? I will gladly answer additional questions if any of you experts have them. Thanks in advance for the great help from this forum.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Engine Electrical Crash

Did you check the main circuit breaker on the engine with a meter (Don't just push the reset and think it's ok)? Also check the square fuse on the main starter solenoid and make sure it didn't fail (again with a meter, looking doesn't help)
 

G-Daddy

Petty Officer 2nd Class
Joined
May 3, 2002
Messages
197
Re: Engine Electrical Crash

We just checked that there was 12v at the back of the starter and there was. Visually checked the main circuit breaker. The boat is about 5 hours from home right now, but I can call a guy to check those things tomorrow morning. Thanks.
 

G-Daddy

Petty Officer 2nd Class
Joined
May 3, 2002
Messages
197
Re: Engine Electrical Crash

Turns out it was a broken wire. The original owner of the boat had bypassed the kill switch. What he did was to put a piece of black automotive wire between the purple wires. One end was crimped and heat shrinked, the other end just had a butt connector. The wire corroded and separated at the end of the butt connector leaving us dead in the water. Glad it was something stupid simple.
 
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