Replacing 470 starter with pmgr starter

[78 Thompson]

This is on a 1978 mercruiser 470
I've read a lot of threads about how to wire the new pmgr starter, but am still a little confused.
I get that you have to run a new wire from the slave solenoid to the starter solenoid, but then everyone says you need a new positive battery cable.
So do I leave the original battery cable hooked up to the slave solenoid, and then run another one from the battery to the new starter? So I would have 2 positive cables?

 

[Scott Danforth]

There is no difference in wiring a PMGR vs a direct drive starter. They both have a B terminal and an S terminal

 

[stonyloam]

The answer to your question is yes. Your new battery cable goes to the large terminal of the starter. Originally your slave provided the current directly to the starter motor, now it just supplies voltage to the solenoid, the new battery cable provides current for the starter.

 

[78 Thompson]

Not positive on which terminal I connect the wire on the slave solenoid to run to the starter solenoid, the big one or the one with the purple wire to the coil?

 

[achris]

Here's what I'd do...

Put the new starter in place, replace the heavy yellow cable that goes from the slave solenoid with one a bit smaller, around 6mm, and connect it to the 'S' terminal on the new starter motor solenoid. Get a new battery cable and run it to the big terminal on the new starter motor solenoid... The new 'yellow' wire goes on the same terminal it came off, the big one that isn't the one to the battery or battery switch.

The small terminal with the purple/yellow wire on the slave solenoid should have nothing else but that wire on it...

Chris..........

 

[78 Thompson]

Ok sounds good, thanks!

 

[78 Thompson]

Well I pulled my new starter out of the box and there are no markings on the starter solenoid.
There are 2 small terminals and the big one in the middle. Which one would be the S terminal? And what does the other one do?

 

[achris]

Post a photo of the back of that starter motor... Big one is where the new battery cable goes on, the 2 small ones... One will be 'S', which you could find with a multimeter, should show continuity to the frame, and the other could be an 'I' terminal, which will have power applied to it when the starter is engaged. Usually used with points ignitions to feed full power to the coil during cranking, but you have that with the old starter solenoid, so you can ignore it. If you meter that terminal, it will have nothing going anywhere..

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

 

[78 Thompson]

I will try to post a picture up tomorrow. I'm at work now.

 

[78 Thompson]

Ok here is the picture. I did check for continuity and the terminal on the right has continuity.

 

[achris]

OK, then that's the 'S' terminal. (If you do put the lead on the wrong one, nothing bad will happen, it just won't work)....

The other thing I would strongly recommend, paint that unit, primer, then top coat, or you'll be replacing it fairly quickly too. Seawater is very harsh on unprotected surfaces....

Chris........

 

[78 Thompson]

Ok thanks
I might finally get this thing running, now thats summer is about over. Lol