470 Starter Motor Wiring - New Starter with Solenoid

[Rake722]

Hey All,

I got the new engine in this weekend and connected up the starter as I could remember but nothing happens when I turn the key.

I have the slave solenoid still present but have removed the voltage regulator and stator being the only difference from before.

I have battery Red going to the left large stud on the slave, then the other large stud heavy red to the large positive terminal on the starter solenoid.

I then have negative from the small stud on the starter solenoid to ground on the engine block.

I cant for the life of me remember how I had it working.

I should add that its a 1978 engine with an aftermarket late starter.

Any help would be appreciated.

 

[Bt Doctur]

 

[achris]

...I have battery Red going to the left large stud on the slave, then the other large stud heavy red to the large positive terminal on the starter solenoid.

I then have negative from the small stud on the starter solenoid to ground on the engine block.....

If you are referring to the 'S' terminal... Nope. That's the terminal that fires the starter...

Chris......

 

[achris]

Here's the same diagram as Doc posted, but cleaned up a little for clarity...

'Special case' Slave solenoid. 2 configuration were available. The 'standard' solenoid has terminal D as the low current ground, and is tied to ground for the solenoid to work. The original '470' slave solenoids had this terminal as the 'I terminal to provide full voltage to the coil+ during cranking. With that solenoid, DO NOT tie it to ground, bad things will happen.

If you still have the 470 slave, then leave that terminal blank (or going to the coil+) If you have a new solenoid where the 2 small terminals are the low current winding, then it needs to be tied to ground. To work out which solenoid you have, just use a multimeter and check to continuity between the 2 small terminals. Have continuity, tie one to ground. No continuity, then that is the 470 'special' solenoid. If you have the 470 solenoid and not sure which small terminal is which? Put one meter lead on the steel mounting bracket (of the solenoid) and find the terminal with continuity to it. That will be the 'S' (start) terminal. It may also be marked on the solenoid.



Chris...........

 

[Rake722]

Thanks Chris thats great info. Ill need to go down to the boat year and see what I have over the coming few days.

Taking a day off today, need to recoup some energy.

Thank you

 

[stonyloam]

OK Iread Chris’s reply am a little confused. If you have the original 470 slave it is grounded through the case, not a terminal. There are 4 terminals, two large and two small. One large has constant battery +12 v, the other goes to the s terminal of the starter solenoid. You have a r/y going to one small terminal, purple going to the coil + on the other. YOU NEED TO RUN A NEW HEAVY BATTERY CABLE DIRECTLY FROM THE BATTERY POSITIVE TO THE LARGE STUD ON THE STARTER. When you hit the key the voltage is applied to activate the slave and closes the contact, that applies battery voltage to the new starter SOLENOID and the coil +. The new starter solenoid closes and applies battery voltage through the new heavy battery cable to spin the starter motor. I think Chris says the same thing, but you seem to have left off the new heavy starter cable to the battery to the starter. But than again I am confused

 

[achris]

.... When you hit the key the voltage is applied to activate the slave and closes the contact, that applies battery voltage to the new starter SOLENOID and the coil +. The new starter solenoid closes and applies battery voltage through the new heavy battery cable to spin the starter motor....

I think he has a battery cable going to one large terminal on the slave, then from the other large terminal to the main terminal of the new starter. There's nothing to 'pick' the new starter's solenoid. :noidea:

Chris........

 

[Rake722]

Well she is now cranking but the wiring is not as you guys describe.

From the Slave - Red 12V Battery connected to left big stud
Red 12V from right hand large stud goes to Starter solenoid Large stud

Left small post on slave is factory yellow red
Right small stud on slave is factory purple green

Nothing connected to one small post on the starter solenoid.

She cranks over like a goodn.

Should I re wire or leave as is ?

 

[achris]

Photos?

 

[Rake722]

Not got a pic but made this

 

[achris]

I assume that little squiggle between the big terminal on the start and the little terminal above it is a wire.. if so, then that's fine. No problem leaving everything as it is.
The only 'issue' is that it means the solenoid passing very high current and meaning one more switch point for losses.

Personally, I'd change it.... But as long as it works...

Chris...

 

[Bt Doctur]

If you have the newer style starter with the attached solenoid then wire it according to achris`s post. cant see using 2 solenoids to pass main battery cable current to starter.
Battery cable to starters main post.
The pic with the squiggly wire has the wire removed and a wire run from that post to the large right side post of the slave
The large left side just needs a 16 or 14 Ga wire to battery power

 

[Rake722]

Thanks All.

i may jist do that and wore it up the way Chris mentions. Just need to understand the word specs (GA) at each location.

chris the squiggly line is a jumper that came with the motor.

 

[stonyloam]

Yeah, you have it wrong to the point of being dangerous. That starter is designed with a internal contact in the solenoid designed to handle the starter current draw DIRECTLY from the battery through a heavy battery cable. Right now you are drawing all of your starter current through the slave contacts. The wire from the large lug to the s contact, while it will work is The wrong way to wire it. Like the doctor says, replace the wire from the solenoid to the s terminal with a smaller one and get the correct heavy cable to run from the large lug on the starter to the battery. The way it is currently wired you risk failure of the slave contacts and overheated wiring.

 

[Rake722]

Thanks Terry,

i will ne doing this once I get my priming issie sorted.

i am however unsure which is the s terminal on the starter.

 

[achris]

The one that the wire is connected to that is also on the big terminal (the small squiggle in you diagram). If you have a multimeter, it will be the small terminal that has continuity to ground....

 

[stonyloam]

The battery cable goes to the heavy lug on the solenoid. The wire from the slave goes to the terminal that you currently have jumpered to the A terminal. When you turn the key to start the slave activates, sends current to the solenoid s terminal which activates the starter solenoid which closes and the starter runs.

 

[stonyloam]

The way you have it wired now, when you hit start the current goes to the lug on the solenoid then through the jumper to activate the solenoid which allows current to run the starter. It will work, but is a long run with more resistance than a heavy cable attached directly to the battery. Your starter should spin better with the new cable.

 

[achris]

.... Your starter should spin better with the new cable.

This....

 

[Rake722]

Well now that I’ve sorted the oil pressure issue this is next.

tjen the shift shaft blowing in to the shift cable void .... 42 year old boats eh.....