2007 Mercruiser 4.3mpi starting/alternator problem

[msswany]

I have 2007 Mercruiser 4.3mpi, Right now when I turn the key on I have no power. If jump power from battery to the excite wire on the alternator I get power and can crank/start the engine. Where could I be losing the power to the ignition?

 

[Don S]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

What is the serial number of your engine. Year means nothing.

 

[msswany]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

0w689482

 

[Don S]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

You afre going to have to find out where the open is in the system. Most likely a fuse or circuit breaker. when you jump to the excite wire you are just powering up the system backwards.

There should be a square fuse on the starter solenoid that could be the problem, then on to the engines 50A main breaker, then on to the instrument panel with a 20A fuse in the red/purple striped wire going to the ignition switch B terminal.
Any one of those could be the problems.

 

[msswany]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

On the 50A main breaker... should the red reset button stick in? and which position should the little yellow arm be in? Thanks

 

[Don S]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

Is this the type breaker you have? Even if it's not tripped, you need to test both legs of the breaker with a meter to make sure it has power to it and coming out of it. Don't just assume it's ok by looks only.

 

[msswany]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

It has that type of breaker, but it ended up being the 15amp fuse on top of the engine

 

[Don S]

Re: 2007 Mercruiser 4.3mpi starting/alternator problem

Should have know, just looked at your profile and noticed you have a Tahoe boat.

Sure would be nice if they would learn how to wire the engine in properly.