Exciter wire

[jgstrickland]

Does the exciter keep constant current going to the Alternator? Or does the Alternator once excited turn the current off?

James

 

[John T]

Im NOT any Alternator expert, see what Jim N has to say. HOWEVER as I understand it, the little No 1 spade Exciter terminal, on the GM 10SI Family of 3 wire alternators, would initially draw current from the 12 volt battery source, but once the alternator is up to speed and self exciting, its like 12 volts is then at that terminal (internaly via the alternator) so there wouldnt be any current draw from the battery. I = V/R but theres no potential difference if the battery and terminal are BOTH at 12 volts so no current draw.

Once the alternator is self excited and spinning you could even turn off that (remote initial excitation circuit) connection and she will continue to operate

Am I wrong??? Jim?

John T

 

[teddy52food]

You are right. I once wired a tractor with a starter push button to excite it. Worked good. Someone wired it wrong & it was draining the battery.

 

[Janicholson]

You are not wrong, it is handled by simple electronics. Jim

 

[jgstrickland]

My dad and I wired the Alternator so that it would recharge the battery. The test meter showed it charging but the Alternator would smoke after shut down of the tractor. What is wrong?

James

 

[Dalex]

I wire my exciter wire to the headlight switch. I just flash the lights after startup , and It's goood to go all day. But ya gotta remember to do it !!

 

[old]

Sounds like you have it wired wrong in some way. If you used the common Delco 10si then yes the excite wire can be hot while the engine is running. It does need to be - ground and you need a diode etc in the #1 wire to keep it from back feeding the ignition system. The #2 wire goes to the big charge stud and the wire from that stud goes to the amp gauge. If you have it wired like that you may have a bad alternator and even if new it does happen

 

[jgstrickland]

Ok, here is what I have. A three terminal starter with
#1 post going to the amp meter right side,

#2 post going to the battery bolt on the back of the Alt. (jumper if you will)

Battery bolt going to left hand side of Amp meter if you were looking at the back of the meter.



Amp meter right side also has wire going to the selonoid hot post side.



James

 

[jgstrickland]

So if you run at night with lights on you are also exciting the Alternator continously?

James

 

[mkirsch]

The way you have it wired, it sounds like your excite wire is ALWAYS hot. No wonder it keeps burning up.

The wire running to the #1 terminal has to be switched. Normally it is connected to the ignition switch on the same post as the wire running to the coil. You also need a diode in the line to keep the alternator from backfeeding the ignition coil and keeping the tractor running.

 

[jgstrickland]

So if I understand you right I can take the #1 wire run it to the idot light (diode) then on to the ignition swith for the hot. My ignition switch is a simple on off switch with no accessories. I use it to simply start the tractor then switch the current back off (no momentary to the switch).

James

 

[Janicholson]

The nimber 1 alt terminal must be connected top 12 volts to start the charging. It should not be connectwed to a always hot terminal (which it is now)
Connect it to the ignition coil supply (if it has a ignition resistor, it should be before that resistor) The wire needs to have a side marker light (not LED) bulb in the circuit. (one bulb terminal to the #1 spade terminal, the other to the ignition as described here. THis is the idiot light needed to make the Alt work and not keep the engine running from the alt feeding voltage to the coil. (it cant send enough through the bulb so the engine stops.)
Jim

 

[Owen Aaland]

The #1 terminal is connected to the rotor through one brush and then back through the other brush to the regulator which normally has that brush grounded. As the voltage rises to the maximum setting the regulator opens this connection to ground which then stops the alternator from charging. The rapid switching from ground to open on this circuit is what controls the voltage.

The #1 terminal is also connected internally to the diode trio. As long as the alternator is charging there is charging voltage supplied to this terminal from the alternator itself. This connection is what allows the alternator to continue to charge even if the voltage applied externally to the #1 terminal is cut off. (Connecting this terminal to the light switch will continue to back feed the lighting circuit even when the lights are off.)

Since the regulator has the connection from the rotor normally grounded with the engine off if the #1 terminal is not switched this terminal will continue to energize the rotor causing a constant drain on the battery.

 

[jgstrickland]

Items on tractor
delco alternator with 2 spades #1R and #2

Amp gauge with two studs (bolts)

Solenoid 2 big post 1 small center post

Simple on off ignition switch (not momentary)

Idot light

Magneto with run off switch on column

 

[charlieu]

I have a bunch of different wiring diagrams out on my website, charliesrepair dot com, There are different diagrams for lots of Red tractors with Delco and Hitachi alternators. I also have diagrams with 6 volt coils and resistors and also 12 coils. Check it out. These diagrams are easy to follow. I hope this helps, Charlie

 

[jgstrickland]

Sorry but no help, I left out that the system was 12v. I need a diagram for dummies I guess. 12v battery, starter,delco 3 wire Alt, solenoid 2 big connetions and one little center one, Amp meter to poles on the back, Ignition switch (simple on/off no momentary or accessories side to it, just turn to on to start the tractor via starter then back to off postion) and a idot light. All the battery is doing right now is starting the tractor. There are no diodes or resistors in the wiring however maybe in the alternator. the tractor runs off the magneto once fired up. Help please!!!!

James

 

[GarryinNC]

If you have a magneto, the alternator excite wire does not need to be hooked to the ignition switch at all. That switch just grounds the magneto 'p' lead to kill the engine. There are several ways to accomplish what you need: a switched 12volt supply to alternator terminal #1. You do need a basic understanding of 12 volt DC electrics.

Garry

 

[Janicholson]

This works and is automatic.
Purchase at NAPA a oil pressure switch that has 1/8" pipe threads, and is normally open closes at 5 PSI. This switch is placed in the oil pressure port on the block using a "T" and a short nipple to allow both to work. The switch has two terminals. One goes to the #1 connection on the alt, the other goes to the battery connection at the starter. No other items are needed. The switch starts the alt when the oil pressure is up, and shuts it off when the engine stops. Fool proof. Jim

 

[Janicholson]

Diagram for post just made.

 

[charlieu]

Well you are correct I do not have one drawing like your tractor. But, If you look at the H-M Delco w/magneto wiring diagram you will see one way to excite your alternator. If you have other wiring needs check out the wiring diagram for a 350-450 Delco 12 volt coil. This diagram will show how the solenoid (my diagram calls it a relay) is wired to operate the starter.

 

[jgstrickland]

Ok I can add the toggle switch, my tractor does not have a oil switch. I also have a 3 post solenoid in my wiring, where does it fit in? And do I need the diode on the exciter wire?


James

 

[Janicholson]

The toggle can be a momentary contact push button normally open single pole (two terminals)
The oil pressure switch is "T"ed into the existing oil pressure line where it connects to the block. The switch is purchased at NAPA. as described earlier. As shown in the other Photo, or as described by me in the oil pressure port. with nipple and T. Jim