SA Wiring Issue

[Doug Kieta]

I am adding a 1-wire alternator conversion to my 1949 Super A. Does anyone have a wiring diagram that shows the connections to the back of the 3 position switch (low charge/high charge/lights). Appreciate any help offered.

 

[Janicholson]

I am adding a 1-wire alternator conversion to my 1949 Super A. Does anyone have a wiring diagram that shows the connections to the back of the 3 position switch (low charge/high charge/lights). Appreciate any help offered.

A three position Light switch has no connection to the charging system at all. The 4 position switches did have control of earlier generators, but the three positions on your switch are Off Dim Bright turning from CCW to CW. There is no connection to the new alternator other than a 10 gauge wire to the amp gauge from the alternator. Change the polarity of the amp gauge so it reads correctly. change the polarity of the ignition coil (negative to the distributor) and put in 12v bulbs. Jim

 

[used red MN]

There is a diagram in this post by jvermast it is for a 3 wire alternator but all you have to do ignore the two wires that go to the 1 & 2 terminals on the battery.
YT post with wiring diagram Just pretend they are not even there. The wire coming off the ammeter to the left of the diagram should go to the terminal on the light switch that powers the fuse. What kind of a coil are you using? If you use the original 6 volt coil you will need an approximately 1.5 ohm resistor to place in the power lead to the coil. I am going to have to find a 1 wire alternator diagram for Farmalls. I had a link to one before the site software switch over but it no longer works.

 

[RedMVa]

There is a diagram in this post by jvermast it is for a 3 wire alternator but all you have to do ignore the two wires that go to the 1 & 2 terminals on the battery.
YT post with wiring diagram Just pretend they are not even there. The wire coming off the ammeter to the left of the diagram should go to the terminal on the light switch that powers the fuse. What kind of a coil are you using? If you use the original 6 volt coil you will need an approximately 1.5 ohm resistor to place in the power lead to the coil. I am going to have to find a 1 wire alternator diagram for Farmalls. I had a link to one before the site software switch over but it no longer works.

Bob M’s diagrams has all references, 1 wire, 3 wire, gens. You really shouldn’t run a 1 wire to the amp gauge, should be run to the positive battery cable stud on push button or solenoid. Then change out amp gauge for a voltmeter, wire appropriately.

 

[used red MN]

Bob M’s diagrams has all references, 1 wire, 3 wire, gens. You really shouldn’t run a 1 wire to the amp gauge, should be run to the positive battery cable stud on push button or solenoid. Then change out amp gauge for a voltmeter, wire appropriately.

RedVa, for a tinkering around Super A wiring through the ammeter is fine. He will just be starting it occasionally and maybe have a few lights on it. Now if it is a cab tractor, with a heater blower, A/C clutch and running whatever monitors or other electronic equipment I would agree sent all those amps direct to the battery cable and the feed point they are all being drawn. Monitor it with a volt meter as you suggest. JMHO

 

[BarnyardEngineering]

We need to get Bob M's 6 wiring diagrams all together in one place.

 

[Janicholson]

There is a diagram in this post by jvermast it is for a 3 wire alternator but all you have to do ignore the two wires that go to the 1 & 2 terminals on the battery.
YT post with wiring diagram Just pretend they are not even there. The wire coming off the ammeter to the left of the diagram should go to the terminal on the light switch that powers the fuse. What kind of a coil are you using? If you use the original 6 volt coil you will need an approximately 1.5 ohm resistor to place in the power lead to the coil. I am going to have to find a 1 wire alternator diagram for Farmalls. I had a link to one before the site software switch over but it no longer works.

With respect, 1 and 2 terminals on the alternator instead of battery in the first sentence (I think you meant). The foundation of assessing a charging system by looking at an on board meter has gone the way of idiot lights. Either an amp meter, or a volt meter can be used but both depend on two conditions, the first is looking at them every few minutes of operation, the second is having a clue as to what one is looking at. If I recommend wiring a "one wire" alternator. I also think a fuse link or high amp fuse holder of 5% greater than alternator amp rating be in that single wire in the circuit to limit fire hazard and melted components. Jim

 

[used red MN]

With respect, 1 and 2 terminals on the alternator instead of battery in the first sentence (I think you meant). The foundation of assessing a charging system by looking at an on board meter has gone the way of idiot lights. Either an amp meter, or a volt meter can be used but both depend on two conditions, the first is looking at them every few minutes of operation, the second is having a clue as to what one is looking at. If I recommend wiring a "one wire" alternator. I also think a fuse link or high amp fuse holder of 5% greater than alternator amp rating be in that single wire in the circuit to limit fire hazard and melted components. Jim

Yes, disregard circuits to 1 & 2 terminals on the alternator. Thanks for the correction. Now you can just follow the diagram Barnyard posted.

 

[Doug Kieta]

All these responses assume the tractor has an ignition coil. My SA is outfitted with a magneto. Does this change any of your opinions on how to wire the alternator so it keeps the battery charged?

Thanks for the help.

 

[RedMVa]

Oh

RedVa, for a tinkering around Super A wiring through the ammeter is fine. He will just be starting it occasionally and maybe have a few lights on it. Now if it is a cab tractor, with a heater blower, A/C clutch and running whatever monitors or other electronic equipment I would agree sent all those amps direct to the battery cable and the feed point they are all being drawn. Monitor it with a volt meter as you suggest. JMHO

it’ll work fine, I’ve done it once or twice that way, I prefer the voltmeter. Simpler imho and keeps that charge wire out of boxes and dashes. Janicholson’s point about a fuseable link would be best option and should be done if running it to the amp meter

 

[BTfromBG]

All these responses assume the tractor has an ignition coil. My SA is outfitted with a magneto. Does this change any of your opinions on how to wire the alternator so it keeps the battery charged?

Thanks for the help.

I would suppose not, so long as you disregarded the connection from the amp meter to a disturbitor.

 

[Bob M]

All these responses assume the tractor has an ignition coil. My SA is outfitted with a magneto. Does this change any of your opinions on how to wire the alternator so it keeps the battery charged?

Thanks for the help.

Nope! Wire per the diagram above, only omit the wiring/switch to the ignition coil.

 

[Doug Kieta]

So then what happens to the wire coming from the ignition switch to the coil. Where does it connect?

 

[RedMVa]

All these responses assume the tractor has an ignition coil. My SA is outfitted with a magneto. Does this change any of your opinions on how to wire the alternator so it keeps the battery charged?

Thanks for the help.

Didn’t assume anything, doesn’t really make any difference. Just makes it simpler to wire

 

[RedMVa]

So then what happens to the wire coming from the ignition switch to the coil. Where does it connect?

Nothing, you should only have one wire from switch to the mag, it’s a grounding switch, nothing more

 

[RedMVa]

S

Nothing, you should only have one wire from switch to the mag, it’s a grounding switch, nothing more

Should say with a grain of salt that I’m basing what I said on it was still original wiring

 

[used red MN]

The wire from the ammeter to the ignition switch shown on the diagram is removed or simply not there. The ignition switch for the magneto only closes contacts to a ground to kill the spark. Do not try to send power to a magneto it will damage it. I see someone else has replied they may be saying the same t thing.

 

[Doug Kieta]

Bob M,
Can you help clarify this point for me. If I remove the ballast resistor, ignition coil and distributor from your schematic #5 for a Hitachi 14231 alternator, how does the ignition switch function on a magneto system? Also, I am using a Denso mini alternator that fits quite nicely under the hood. Does it require a minimum pully speed to energize it, or will any speed work. I am using the belt off the SA fan that was previously used for the generator. Thanks.

 

[used red MN]

Bob and I explained that, you simply need no “ignition switch that pertains to the battery system” on your tractor. You have a working magneto kill switch or ignition switch on your tractor before with the 6 volt generator correct? If so when your doing the alternator and lighting wiring pretend that everything to do with the old mag kill switch is on a tractor in the next county, leave it as it is. Print the diagram off and scribble out the ignition switch, wiring to the coil and the distributor if your brain can’t ignore it. If you would be using a 3 wire alternator you would add an oil pressure switch to replace the disconnect a battery ignition switch would provide on a distributor system. A one wire does not need to have a disconnect to the excite circuit like a 3 wire does. I have heard that one wire alternators can have a parasitic draw that will kill the battery if they set unused to long. I can’t verify that I have not been around any tractors that use them. I always put on the less expensive 3 wire Delco 10si.

 

[Doug Kieta]

Now I get it. Thanks.