Mercruiser 5.7 no start/power to the starter

[toddsallee]

Mercuiser 5.7 no start
I turn the key hear a fast clicking but starter not turning the flywheel. Replaced the starter still same problem.

 

[Bondo]

Ayuh,..... Sounds like a dead battery,.......

 

[Scott Danforth]

Mercuiser 5.7 no start
I turn the key hear a fast clicking but starter not turning the flywheel. Replaced the starter still same problem.

what troubleshooting did you do?

its almost never the starter

I would start with testing the batteries and checking voltages. most likely you have a bad connection somewhere or a bad cable.

step 1 - have the battery load tested
step 2 - clean every battery connection with a wire brush or 150 grit sand paper and make sure they are clean and shiny enough your mother would eat off them

 

[achris]

Use your multimeter across each connection. Shouldn't be more than 0.1v drop across any connection. Don't forget the negatives.

Chris...

 

[QBhoy]

failing the above ideas...check you don't have water in the cylinders and it is locked up...take the plugs out and try it...if she turns over then..you have issues most likely caused by water from the manifolds

 

[j cat]

Mercuiser 5.7 no start
I turn the key hear a fast clicking but starter not turning the flywheel. Replaced the starter still same problem.

the fuses have some corrosion ......last year I cleaned those fuses and the voltage is 12.5volts when turned the key on ignition mode..the voltage prior to the fuse cleaning drops 10 volts..my starter spins faster after the fuse cleaning ...
check the wiring connections inspect the ignition switch use a voltmeter..
I have my mercrusier OEM manual 2 books ...