alternator

[little john]

Is there any advantage to a 3-wire alternator as compared with a 1-wire when converting to 12 volts?

Thanks for your thoughts.

 

[J Hamilton]

With a 3 wire, wired correctly, it will start charging when the engine starts. A one wire, you would have to speed the engine up to excite it to charge. I always do 3 wire myself

 

[little john]

Thank you. Sounds like it's a good idea to have a 3-wire.

 

[timcasbolt]

(quoted from post at 16:07:16 10/27/22) Thank you. Sounds like it's a good idea to have a 3-wire.

n addition to Mr. Hamilton's comment, I have also found that the self-exciting regulators needed for a 1-wire don't last as long as the oem.

 

[miangus]

I had trouble with the one wire in my Farm-All 400, upgraded to a three-wire regulator and a small light and all is well. Also, when upgrading tractor like a JD 40 20 the light still can me made to work.

 

[Blackhole49]

FYI. My 8n had a one wire on it long before I got it 20 years ago. A quick burp of the throttle after it starts and it is charging. Never had a problem.

 

[caterpillar guy]

We put 3 wires on so they don't have to be wound up cold in winter. They charge from the start unlike the 1 wires. there is only one more wire. And it can be connected to the switch so it is dead when shut off. We have a toggle switch on our MD to excite it then shut off when done. And of course it has been left on a few times to come back to a dead battery in the morning.

 

[jimtrs]

(quoted from post at 12:56:26 10/27/22) Is there any advantage to a 3-wire alternator as compared with a 1-wire when converting to 12 volts?

Pretty much as was said already.
Interested in what might be considered disadvantages?
I'll list a couple anyway. By the way, none of the following is really a big deal, to me, at least

Need an alternator pigtail plug
Need to run two additional wires (one can usually be the pigtail wire itself, the other needs to go to a switched power source. Depending on the tractor this can be easier said than done. That being said, most are easy)
Need to add in either an idiot light or a diode in the excite line (can get a pigtail with a diode already wired in)
May need to "clock" your alternator to get the plug in a good position

Again, none of these are really a big deal. Just some additional steps over a one wire.
IMHO the advantage of the 3 wire outweigh these additional steps.