1990s 4.3 cobra I/O wont crank. Help!

[ryan2022]

Hi guys,

The families boat has a 4.3l cobra I/O and all of a sudden will not turn over.

The battery is new and fully charged, accessories work....the ignition switch and tether cutoff both work fine. I've jumped them both with the same result.

Theres power getting to the engine, because I hear the whine of what appears to be an oil or fuel pump.

There is NOTHING getting to the starter. Fuses are all fine, as are the breakers (newer 4.3)

Could this be a starter or starter solenoid issue? Strange the boat has been flawless until it quit completely.

Any thoughts are appreciated.

 

[BigCahuna]

Well. the solinoid is what supplies power to the starter, so that's where I would start first. Get a meter set on 12 volts dc ,have someone hit the key, and read what your getting. If you can jump the big terminal on the solinoid to the big one on the starter, if should turn over if all the wiring is clean and tight. Before you try jumping the terminals, Touch the wiring cables with your hand to be sure it's tight, don't just look at it.,,

 

[mk378]

There's usually a switch that requires the gear to be in neutral for the starter to work.

Try jumping the terminal on the starter for the small wire to the battery + terminal.

 

[ryan2022]

Thanks guys! I will try those things. Much appreciated!

 

[joegreen]

You could try tapping on the starter if you want to try something quick

 

[Donald]

Take one lead of a car jumper cable and connect to battery and other end tap on small wire input to starter solenoid. Next the solenoid output to the starter. Could be battery cables at either end. Corrosion in the ground.

Make sure engine area is free from gas fumes as you are likely to make a spark or two in this testing.

 

[WyrTwister]

Precisely , I was thinking about gas fumes , also .

If you have the boat connected to shore power , might place a box fan to blow fresh air into the engine compartment , a while before you start making sparks , to purge out any gas fumes .

If you have adequate battery power , cables & connections OK , the starter is actually OK , you should be able to get the starter to crank .

If it starts & runs is another chapter in this story .

Best of luck to you ,

 

[Donald]

I carry a small DVM on my boat to measure voltage, etc. Good to know the general layout of the wiring. You have ignition switch, neutral safety switch, harness and harness connector.