Alternator basics?

[sellener777]

Trying to understand alternator wiring. Was doing some
rewiring of lights on Oliver 1655.



Tractor has alternator, tractor does not have external
voltage regulator anymore.



1) When you remove external regulator does that mean u
buy a different alternator. Or u can still use alternator
and wire it differently.



2) current alternator that is on I am calling a three wire,
as it has three wires coming off. Big battery, small 1,
small 2.



Small 1 I am calling exciter wire.



Are alternators called 1 wire vs 2 wire vs 3 wire
fundamentally different devices, or the same device can
be wired differently for different reasons?

 

[Jim.ME]

(quoted from post at 12:08:02 07/05/22) Trying to understand alternator wiring. Was doing some
rewiring of lights on Oliver 1655.



Tractor has alternator, tractor does not have external
voltage regulator anymore.



1) When you remove external regulator does that mean u
buy a different alternator. Or u can still use alternator
and wire it differently.



2) current alternator that is on I am calling a three wire,
as it has three wires coming off. Big battery, small 1,
small 2.



Small 1 I am calling exciter wire.



Are alternators called 1 wire vs 2 wire vs 3 wire
fundamentally different devices, or the same device can
be wired differently for different reasons?

What brand alternator? Pictures?

Yes, if the alternator had an external regulator, you need a different alternator if you remove the external regulator.

Depending on the alternator brand external and internal regulated alternators may have three wires. So, without knowing what you are looking at for an alternator any answer is a guess and could result in much smoke. JMHO

 

[sellener777]

Heres some pics.

 

[sellener777]

Id like to wire with the led idiot switch.



As like diagram I attached.



Tried it but led light stays on after tractors running.



Resting voltage measured at starter positive post was
12.4-12.6



Voltage with lights on tractor running at same spot was
13.8



Seems like that means alternator works?



But led light never extinguishes as expected.



Wired lead 2 off alternator to starter positive, and also to
positive battery on alternator. Both ways seem no
different.



Lead one on alternator wired through idiot light to
ignition.

 

[sellener777]

Attached a video..this is basically what I was trying to
do without success it would seem.

https://youtu.be/QVUL0S704AE

 

[wore out]

A Delco 10SI alternator needs a certain amount of current fed INTO the #1 ''excite'' terminal to make it start charging.

As GM designed them, a resistor, resistance wire and/or (typically) a #194 lamp were used.

Your LED draws/passes too little current vs. the OEM resistor or a #194 lamp to ''excite'' the alternator.

Your options are to use an incandescent indicator lamp similar in current draw to a #194 or shunt your LED lamp with a resistor.

A 10 Ohm 10 Watt resistor would be a good starting point.

With a resistor of the correct value shunting your LED the LED will still function as a charge indicator and the shunt resistor will pass enough current to ''excite'' the alternator at startup.

10 Ohms MAY work or you may have to adjust the value up or down a bit to accomplish both the ''excite'' and charge light functions.

This post was edited by wore out on 07/05/2022 at 03:17 pm.

 

[Jim.ME]

That is a three wire Delco type alternator with an internal regulator. It would not use an external regulator.

 

[sellener777]

Ok, that might make some sense.



So while tinkering and by accident



Tractor running led light on (not supposed to be) I was
multimetering all over trying to piece together what I have
going on and I accidentally touched the multiprobe to
number 1 and 2 and or ground.:not sure what touched
but had some sparks and led light went off, and system
appeared to be definetlyncharging well..



Shut it down and restarted hoping maybe I fixed it.
Maybe some type of polorizing issue.



Not on restart did led function..



Intentionally touched probe into number 1 and 2 wire area
and was able to replicate led turning off and charging
system operating well..



On shutdown u can watch led light come back on as
engine dies





Sooo. Perhaps it is the case S you stated that the led is
not exciting enough but my shower of sparks was???

 

[sellener777]

Hey wore out.how does one add shunt resistor
conceptually?



Some type of fuse type thing inline in the same circuit
weak led is in?



Thx everyone really appreciate it!

 

[Mike(NEOhio)]

My 1550 was set up like that by PO or PPO. He had one terminal with a home-made jumper to the output, correct there, but the white wire was on it too. He told me it was OK if used regularly but would discharge if it sat. The battery was sad so I thought that was the problem. I found a 50 milliamp draw when the key was off, killed a brand new battery.

 

[sellener777]

So the 194 bulb works as described.thx!



Might try the resistor as the led fits nicer in dash.



Thanks

 

[wore out]

(quoted from post at 14:21:25 07/06/22) So the 194 bulb works as described.thx!



Might try the resistor as the led fits nicer in dash.



Thanks

YAY!

Nothing like SUCCESS and a low-cost ''fix'', as well!


(As to your other question, to be clear, ''shunting'' the LED lamp with a resistor means to connect them in parallel.)

 

[rvirgil_KS]

I accidentally touched the multiprobe to
number 1 and 2 and or ground.:not sure what touched
but had some sparks and led light went off, and system
appeared to be definetlyncharging well..

Sounds like your probe connected battery voltage from #2 pin to #1 pin thus bypassing (shunting) the LED and supplying enough current to excite the alternator to charge.

You would install a shunt resistor by connecting one end of resistor to one end of LED and other end of resistor to other end of LED. You can do that at any convenient point in the circuit.