5.7 merc starter

[blh1972]

I have an 84 Searay that came with a 5.7 mercruiser that has been upgraded to a 1996 5.7 vortec. the old starter was a 4 post solenoid, the new starter is a 3 post solenoid I have the big red wires and solid orange wire connected to the big post. the yellow/red wire to small post on the solenoid, (But I have a purple/gray wire that used to go to another small post on the solenoid that is not connected to anything) The engine starts right up but I'm not sure what to do with the purple /gray wire. Should it be grounded?
Thanks in advance,
Brian.

 

[Laddies]

Re: 5.7 merc starter

The 4th post is for the coil, it bypasses the resistor when the starter is engaged to supply more voltage to the coil for start up, if the old solinoid will fit use it, although I would buy a new one myself

 

[blh1972]

Re: 5.7 merc starter

So the purple/gray wire needs straight 12volts while cranking, if thats the case then can I put it on the same terminal as the yellow/red wire????

 

[Don S]

Re: 5.7 merc starter

So the purple/gray wire needs straight 12volts while cranking, if thats the case then can I put it on the same terminal as the yellow/red wire????

NO, it doesn't do the same thing as the yellow/red wire.
I don't have Service manual 3 with me, and I know the 84's used the Thunderbolt electronic ignition, so I'm not sure what the purple/gray wire you see is for. Was this the old engine or the new engine that has this wire?
If it's on the 96 it could be for the electric fuel pump if it was a Merc engine. Not sure what you have.

 

[blh1972]

Re: 5.7 merc starter

The block ID#10243880 it is a 5.7 mercruiser with mechanical fuel pump. The engine runs fine with the purple/gray wire tied back.

 

[Bondo]

Re: 5.7 merc starter

My Guess is,......

You've got a Car starter on there.......

 

[blh1972]

Re: 5.7 merc starter

If it is a car starter do I have to change it out??
And how do I tell?

 

[blh1972]

Re: 5.7 merc starter

Bump...

 

[Coors]

Re: 5.7 merc starter

It will have what looks like heavy duty screen over the openings.

 

[blh1972]

Re: 5.7 merc starter

No openings it looks like a sealed small bodied gear reduction type starter.
So if it runs ok without the purple/gray wire then I guess I can leave it tied back???

 

[Laddies]

Re: 5.7 merc starter

This is important, was the new engine marine or automotive. If it was automotive it will have a automotive starter not marine. That auto starter can KILL YOU AND YOUR FAMILY, get it replaced immediately without built in flame arrestors it will only take one start with fuel vapors in the bilge and your boat and everything around it could be gone