[SEL] OT - John Deere wiring diagram needed

[Listerdiesel]

On Apr 1, 2005 3:16 PM, bill at antique-engines.com
<bill at antique-engines.com> wrote:
> Peter - here's what I found:
> A check showed that the light that was staying on was the ALT/BATTERY
> light! Someone has worked on this in the past and had the wrong light in
> the wrong hole.
> The real oil light was going out when it started. I did trace the oil
> pressure wiring. Switched battery +12 to one side of bulb, other side
> right to sender.
> 
> So, now to figure out why the ALT light stays on - I suspect regulator -
> it's a solid-state unit mounted on the shroud, well, sort of in it, for
> cooling I believe - it's an Onnan engine on this 318.
> The stuff the regulator is sealed with is pulling out. Can't be good.
> 
> Bill

OK, that's one solved and another one found! :-))

The alternator light is fed 12V again, and is grounded through the
field winding, so when the field winding gets up to 12V or so then the
light goes out.

Some of these controllers have a special feed for the light, others
have a special winding and single diode just for the light, as the
rest of the output is rectified 3-phase.

Is the alternator (I assume it IS an alternator?) actually charging ? 
If not, then there's your answer. If it is working OK but just the
warning light not working, then suspect either the controller or the
alternator.

Some units use the current through the bulb filament to kick start the
excitation of the field winding, worth remembering if the bulb ever
goes!

Peter
-- 
Peter A Forbes
Email: listerdiesel at gmail.com
Web: www.oldengine.org/members/diesel