Auxiliary Terminal on Alternator

[kjones95206]

I purchased a rebuilt alternator for my Case 580b and the rebuilt alternator does not have an auxiliary terminal. My current alternator connects the auxiliary terminal to an alternator resistor and the other side of the resistor to the hot side of the key switch as shown in the wiring diagram. Is this used to "excite" the alternator? Is it necessary with an only one wire alternator?

 

[Delmer]

I'd need to see the back of your new alternator to give a better guess.
A one wire alternator does not need the excite, it will charge with just the big wire B+ hooked up. The alternator warning light will not work. A voltmeter is easy to install, cheap, and works better than a warning light.

 

[kjones95206]

The tractor has an amp meter; The big wire B+ connects to one side of the amp meter and the the other side of the amp meter is connected to the battery.

 

[Delmer]

that doesn't matter to the alternator, if the amp meter worked before, it will still work.

Personally, I'd remove the amp meter, wire the alternator direct to the battery cable at the starter with only a largish fusible link, then replace the amp meter with a voltmeter. But it will work fine with the original wiring.

I think in a lot of cases, the generators were not powerful enough to raise the voltage that much, and so an amp meter was needed to indicate charge or discharge from the battery. amp meters/ammeters were probably cheaper to make than voltmeters. The problem was you had to understand how charged the battery was for the amp meter to mean anything. An alternator usually either works or not, so it puts the voltage up to 14 even at idle, or it stays 12 and drops fast, so a $2 voltmeter will tell you the alternator is working.

 

[Tinkerer]

I purchased a rebuilt alternator for my Case 580b and the rebuilt alternator does not have an auxiliary terminal. My current alternator connects the auxiliary terminal to an ALTERNATOR RESISTOR and the other side of the resistor to the hot side of the key switch as shown in the wiring diagram. Is this used to "excite" the alternator? Is it necessary with an only one wire alternator?

View attachment 236538

Is the engine a gas or diesel ?

 

[kjones95206]

Diesel

 

[Tinkerer]

That certainly rules out any association for it with an ignition coil.
It may be there to drop the voltage to one of the gauges in dash.
Is there 12v on one side and 6 volts on the other ?
So, did you get it to charge ok ?

 

[kjones95206]

It's my understanding that older alternators had to be "excited" before the alternator would begin charging; Hence the Aux wire going to the power side of the key switch after going through a resistor. Additionally, it's my understanding that newer alternators do not have be "excited" to charge; Hence the absence of the Aux connection. Is my understanding is correct or flawed?

 

[Delmer]

SOME alternators do not need to be excited to charge. typically called "one wire". They've been around since he 70's.

Your new alternator should have a wiring diagram available somewhere. Or post a pic of the alternator terminals you have. Is it installed? is it charging?

 

[Delmer]

oops

 

[hookedondiesel]

Do you have a light on the dash for " Alt" or " Bat"? When the key is turned on. Like "others" have said, post a pic of the back of your new alt, and if possible, your old alt.

 

[kjones95206]

An amp meter is mounted on the dash; no light. I can only take photos of the new alternator because I turned the old one in for the core charge.

 

[Tinkerer]

Is the new alternator charging ?
If not, run the engine rpms up to at least 1500 and see if starts to charge.

 

[hookedondiesel]

Here's a couple of video's that may help you.

 

[kjones95206]

The YouTube videos were helpful. I haven't installed the alternator on the 580B because I'm finishing cleaning the torque converter suction tube. My rebuilt alternator is a Delco-Remy 10SI that is suppose to "self-excite" at 275 rpms. I think that I will try using just the one wire and see how the alternator performs. If I need to wire it to self-excite the alternator then I can add the additional wiring if necessary. Thanks for enlightening me on theses alternators

 

[Delmer]

In my understanding "self excite" is NOT the same as one wire. The top number brings up a Wilson site that has a note for other numbers for a one wire, so don't be surprised if you get nothing with just B+/BAT hooked up. See the little hole where the L in delco should be? poke a paper clip, or small wire in there to ground the tab inside to the case, that will put the alternator to full output while you have it grounded, so you can see that the alternator works. Then hook #1 and 2 to the BAT terminal and it will charge with the regulator, at the correct voltage, then hook up 1 and 2 correctly, one goes to BAT and one goes to the switched ignition wire.

 

[kjones95206]

Thanks Delmer... Do you know the purpose of the terminal in front of and in the middle of terminals 1 and 2?
All of the information that I have found only references terminal 1 and 2.

 

[Delmer]

Ignore the R terminal, the best I can find, Delco says the R terminal is for "tachometer, charge indicator, ADLO system" and gives specs for frequency and voltage conversion.

As far as I know 1 and 2 are standard excite and remote sense. That source said remote sense doesn't need to be connected, and maybe that's true with Delco products, but there's lots of aftermarket voltage regulators so you might have to hook it up. Straight to the Bat term is fine for a tractor.