3 wire alternator

[jim buford]

This message is a reply to an archived post by phil in jackson on February 04, 2015 at 06:13:38.
The original subject was "3 wire alternator".

I am the first to admit I am very electrically challenged but a question for you guys: does it matter whether or not one has to rev the engine to get it to start charging on a one wire? In a matter of minutes after starting the engine is warm enough to rev and how much battery drain will there be in that length of time and the alternator will quickly replenish that drain to the battery won't it if working correctly?

 

[Dollar Bill]

Unlike the 3-wire alternator that charges at idle, the simplified 1-wire alternator need to be revved up to about 1800 RPM before it will start charging.

To see if you can make it work like a 3 wire: Next time you have it warmed up, instead of revving the engine, hook a wire from bat hot and then touch the #1 spade connection (may be hiding under a rubber cap). If charging starts, then shut down and wire a short wire from #2 over to the charge stud, and then a longer wire from #1 thru a marker lamp like a 194 lamp, and then to the coil side of the key switch.

Light should be on with the key on. Once engine goes past 400-500 RPM, the lamp goes out indicating it is charging.

 

[HCooke]

Buy the one wire alternator from this site. It starts charging immediately. Wiring is simple.

 

[JMOR]

Many posts on subject over the years & I can say that all one-wire alternators were not made one wire by use of the same internal regulator, as there are many different such VRs and some will kick in at lower rpm than others. I converted one that will begin charging as low as 1450rpm and with a crank/alt pulley ratio of typical N tractor of 1.43:1, that would be engine rpm of about 1000 rpm......not exactly throwing the pistons through the head. As said, all are not equal in the specific VR, pulley diameters, etc., but overall, I say much adoo about not much of anything. just my 2¢.

 

[HFJ]

my one wire alternator starts charging immediately, at modest engine speed - certainly nowhere near 1800 RPM.

 

[SteveB(OH)]

(quoted from post at 02:52:00 01/03/18) This message is a reply to an archived post by phil in jackson on February 04, 2015 at 06:13:38.
The original subject was "3 wire alternator".

I am the first to admit I am very electrically challenged but a question for you guys: does it matter whether or not one has to rev the engine to get it to start charging on a one wire? In a matter of minutes after starting the engine is warm enough to rev and how much battery drain will there be in that length of time and the alternator will quickly replenish that drain to the battery won't it if working correctly?

To answer the original question, no, I don't think it makes any practical difference if you use a 1 wire alternator or a 3 wire alternator. Once the tractor is started the ignition only draws 3 or 4 amps (I think...) which is negligible. If your battery can't supply that amount of current for a few moments it's time for a new battery anyway.

Having said that, I can tell you that I installed a 1 wire alternator on my 48 8N, and then found that I could wire it as a 3 wire alternator as someone mentioned earlier. Therefore, I can offer experience with both setups.

While I was running as a 1 wire setup the alternator would not start charging immediately, but the engine speed to drive out of the barn was usually enough to get it to kick in, and most certainly running a rotary cutter or getting from one end of the field to the other would certainly get it charging. I could have run my 8N that way for oh, 100 years or so without problems...

But, I like to tinker, and it bugged me that it didn't start charging immediately. It didn't bug me for any legitimate reason, it just bugged me. So, with the help of this board I tried to wire my 1 wire as a 3 wire, and viola !! it worked perfectly and now starts to charge immediately.

I'm happier now, but not for any good reason, I'm just happier... 8) 8)

 

[JMOR]

Great SteveB...glad to see happy tractor'er. Just FYI for other readers, although many/maybe most one-wire VRs will function when wired as 3-wire, ALL will not (D22AC-1) for one & no doubt others are out there among the more than two dozen such devices.

 

[SteveB(OH)]

(quoted from post at 16:13:49 01/03/18) Great SteveB...glad to see happy tractor'er. Just FYI for other readers, although many/maybe most one-wire VRs will function when wired as 3-wire, ALL will not (D22AC-1) for one & no doubt others are out there among the more than two dozen such devices.

Good point JMOR. In fact I have no idea if wiring a 1 wire as a 3 wire can cause damage.

Proceed at your own risk !!

 

[Eman85]

Yes you can wire it as a 3 wire alt, actually a 2 wire as all you need to do is wire a jumper from the main post to the one terminal in the plug. Or you can also just touch a jumper wire to the exciter terminal on the 1 wire and it will immediately begin charging no matter what the RPM.