old merc 3.0 will not start

[searay70]

Hello, I just bought a boat 1970 18' searay and don't know much about them. I put a new 600 cca battery in and it is fully charged. I also put a new starter switch in it because the guy said it needed one. He started it by crossing the starter with a screw driver, so I know it runs. Heres whats going on. I turn the key and the battery gauge moves just a hair. The starter will NOT click or do anything. The shifter also seems to be in neutral. I also checked the fuses under the dash and there all good. Where do I start?

 

[Don S]

Re: old merc 3.0 will not start

Hold the key to start position and move the shifter around. The neutral safety switch may be out of adjustment.

 

[searay70]

Re: old merc 3.0 will not start

I tried that for about 5 minutes but still nothing.

 

[Don S]

Re: old merc 3.0 will not start

What you need to do is check your starting system like in this thread.
http://forums.iboats.com/showthread.php?t=167035

The big problem you will have, is all the information in that post is for the new wiring system as far as color codes go.
For your 1970 engine, you will have to convert the colors to your engine.
Here is a chart to do that.
An oem wiring diagram would help if you have one.

 

[searay70]

Re: old merc 3.0 will not start

all the wires are hooked up and it all tested fine. but still nothing.

 

[Don S]

Re: old merc 3.0 will not start

all the wires are hooked up and it all tested fine. but still nothing.

Then you didn't test it properly.

 

[Bondo]

Re: old merc 3.0 will not start

all the wires are hooked up and it all tested fine. but still nothing.

Ayuh,....... That's Impossible.........

 

[searay70]

Re: old merc 3.0 will not start

ok It turns out i had a bad starter solenoid. I replaced that and now when I hook up the battery, the starter gives one click even when the key is off. Then when I turn the ignition nothing happens.

 

[BAYLINER185]

Re: old merc 3.0 will not start

Something is not wired right if the starter clicks with the key is off. I suspect the starter clicks when the main wire is connected to the battery inorder to make the starter click. I hope in that case the battery is dissconnected when your not around or working on this problem as it sounds as if power is constantly flowing to the starter and may burn up the motor as its not rotating. There should only be 12 volts to the key switch and I belive at one point listed as BAT on the solinoid when the key is Off or in the run position. 12 volts to the other side of the solinoid and key switch when in sart only.

Something is not right. Check the wiring again and dont leave the battery connected or you may find your battery dead, soliniod or starter burnt up or maby even a melted fiberglass mess on the trailer if there is some weird short somewhere.

 

[Coors]

Re: old merc 3.0 will not start

Time to trace and clean all contacts, INCLUDING THE GROUNDS.
Then see if some yahoo miswired it.

 

[searay70]

Re: old merc 3.0 will not start

is the starter supposed to click when you hook the battery up? There is a constant feed to the starter from the battery? Is my starter bad?

 

[Bondo]

Re: old merc 3.0 will not start

is the starter supposed to click when you hook the battery up?

Nope,......

I suspect you have a Wiring Problem,.....
Somewhere Other than the Big wire between the Battery,+ the Starter......

 

[JustJason]

Re: old merc 3.0 will not start

i betcha this boat probably had a lot of water in it and you have multiple problems....
Buy a DMM.... and learn how to use it.
http://assets.fluke.com/appnotes/electricalpower/B0270b_u.pdf

 

[searay70]

Re: old merc 3.0 will not start

well I got her goin. I replaced the bad slave solenoid with a brand new bad solenoid so I tried another one and she fired up. Thanks alot this website is awesome!!!!

 

[searay70]

Re: old merc 3.0 will not start

who makes this mercruiser 3.0 I have been told ford and I have also been told chevy?

 

[Bondo]

Re: old merc 3.0 will not start

Ayuh,....... It's a GM Marine/ Industrial motor......