2004 Larson 180 4.3 Merc Completely Dead

[bnicov]

Here's the problem:
Cruising along last night, the boat went completely dead from cruising on plane. There is no power to anything, none of the electronics work, it does not turn over, nothing whatsoever. We tried to reset the main circuit breaker (50amp) to no avail. The battery voltage shows 12.8volts and we tried a different battery and still absolutely nothing.
Anyone have any ideas on what and where to check before it gets taken into the shop???

 

[Bondo]

Re: 2004 Larson 180 4.3 Merc Completely Dead

Cruising along last night, the boat went completely dead from cruising on plane.
The battery voltage shows 12.8volts

Ayuh,.... I guess it ain't Completely Dead,... The Voltage gauge works,...

What else Works,..??

If it's Just the motor,+ it's systems,...
Check the little square Fuse mounted where the battery cable meets the starter...
'course,... Then ya Gotta find out Why it blew....

 

[bnicov]

Re: 2004 Larson 180 4.3 Merc Completely Dead

Actually, the voltage reading we got was off of a multimeter. Everything on the boat is dead. There is no power to anything on the boat including the gauges.

 

[slowroller88]

Re: 2004 Larson 180 4.3 Merc Completely Dead

Had a similar problem myself, if you have a tehered kill switch, check that. I had a similar problem, turned out the switch wasn't fully engauged, enev with the key in it.

 

[Daviet]

Re: 2004 Larson 180 4.3 Merc Completely Dead

If I am thinking correctly, all the power comes off of the battery cable at the starter. Do you have any extra wires on the battery itself? If you do check the components that are fed by those wires. Check voltage on both sides of you main circut breaker, maybe reset didn't take hold. If you lost all power, and battery tests good, you just have to start at the battery and find you voltage loss. Don't forget to check your negative cable, voltage has to return to battery to complete circut.

 

[searay3]

Re: 2004 Larson 180 4.3 Merc Completely Dead

Look at the cannon plug. Could have vibrated loose or corroded and lost connection.

 

[bnicov]

Re: 2004 Larson 180 4.3 Merc Completely Dead

I run the risk of sounding stupid but a wise man once said that there are no stupid questions.
What is a 'Cannon Plug'???
Thanks for the replies, we're going to really check her out when we get back up to the lake on Friday afternoon.

 

[bnicov]

Re: 2004 Larson 180 4.3 Merc Completely Dead

Turned out there is a 90 amp fuse by the starter motor that is not on any wiring diagram that blew. $30 for the fuse and the boat was good to go. The leads to the alternator touched the exhaust manifold and ended up melting and shorting out blowing this big honking fuse.
BTW, what the heck is a cannon plug???

 

[Bondo]

Re: 2004 Larson 180 4.3 Merc Completely Dead

BTW, what the heck is a cannon plug???

Ayuh,... It's the Big black wiring plug, where the motor meets the Boat,...
It's usually mounted on the motor,+ held together with a hose clamp...