Onan (4K) Starter Electrical Terminals

[SteveW]

Greetings

I discovered some broken and some chaffed wiring behind the starter of my generator. I disassembled it this weekend and am in the process of
replacing some wires.

The three wire harness originating from the alternator stator - two appear to go to the control board and one goes to B+.

That third wire is the one that's broken... from where does it pick up B+ ??

And... I think that I found a broken ring connector on terminal "M" of this diagram. Is "M" also B+ ??

http://www.gmcmhphotos.com/photos/data/500/Starter_no_load_test.JPG

Thanks for your comments - and for all of the information shared here.

Steve W
1973 23'
Southern California

 

[john r. lebetski]

It appears M is ground on the drawing I have. B is batt + and that goes over to K1 which when engaged sends that B+ to S to crank.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[Matt Colie]

> Greetings
>
> I discovered some broken and some chaffed wiring behind the starter of my generator. I disassembled it this weekend and am in the process of
> replacing some wires.
>
> The three wire harness originating from the alternator stator - two appear to go to the control board and one goes to B+.
>
> That third wire is the one that's broken... from where does it pick up B+ ??
>
> And... I think that I found a broken ring connector on terminal "M" of this diagram. Is "M" also B+ ??
>
>
>
> Thanks for your comments - and for all of the information shared here.
>
> Steve W
> 1973 23'
> Southern California

Steve,

The M terminal should have a short stub that goes directly into the starter motor. In this case M means Motor (not engine).
When you power the contactor (solenoid) at the S terminal the contacts should connect B (Battery) to M to crank the engine.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[john r. lebetski]

That makes more sense Matt. That drawing I was looking at is not clear. Basicly just like any old Delco starter
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[SteveW]

Thank you Matt, Thank you John.

Lots of places that I can pick up B+ so no worries on that front.

Something was definitely connected to that terminal though... it's got a broken ring connector. Very curious as to what it might have been.

Seems it ought to supply 12V while cranking - correct ??

I can't get to the coach for a few days - but will do some further exploring.

Thanks again,
Steve W
1973 23'
Southern California

 

[Matt Colie]

Steve,

If the terminal that was on M is broken, then there should still be the stub of the motor lead that goes into the starter. If you don't find that,
then it is time to break the starter down and find out where it went.

If you are comfortable working on this sort of thing, these are really just miniature Delco starters, go for it. If not, take to a local
auto-electric guy. That same starter has been on commercial lawn equipment for decades.

Remember to inspect the starter bracket while you are doing all this. They are known to fail. JimK (I believe) has a steel replacement.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit