3 wire altenator indicator light or diode? Ammeter guage?

[Dwd14329]

If both gauges are on the tractor you can run them both, neither will affect the operation of the other.

 

[Duner Wi]

My TO20 has the excite wire to the start position on the key switch. After starting with the shifter switch, if I turn the key to start it excites the alternator. Sometimes if it idles down it stops charging (shown by ampmeter) and I have to turn the key to start again when I throttle up. At least it don't drain the battery when it's not running.

I should get a diode and wire it in to the run/coil post on the key switch. I see some wire kits on ebay with the diode already wired in on the 2-prong alternator plug. I miss radio shack........

Mad Farmer, Look at your TO20 switch, if it has an accessory terminal attach excite wire to that.. Accessory terminal should be completely seperatee fron Ignition terminal so it should not back feed.

 

[Jim WI]

Yes. It is LED, im sure. I cant find the correct correct replacement fixture so I think I'm going to just leave it as is being that its not causing any issues.

Does the alternator charge? Does it need the throttle opened to make it start charging?

 

[DN-N-TN]

Mad Farmer, Look at your TO20 switch, if it has an accessory terminal attach excite wire to that.. Accessory terminal should be completely seperatee fron Ignition terminal so it should not back feed.

I completely agree. I just used one of my Fords (641) this morning to set out some round bales to the livestock, and I changed it to 12V twenty four years ago. I used a 4-post ignition switch, 10SI three wire alternator. Since both the small post on the alternator need to have power applied to charge, I hooked them together, then to the ACC post on the switch, IGN on the IGN post, AMP meter to the BAT post, and the S terminal from the four post Ford starter relay to the S post on the switch. Of course, the big post on the alternator is hooked to the direct battery current. Since I'm the only one operating my tractor, I wanted key start, but if key start isn't wanted use the old 3-wire tractor starter relay, and disregard the use of the S terminal on the switch. I've got two tractors wired this way---the 641 for 24 years and the NAA for 40 years with no problems and batteries last about 7 years before replacement-------just my 2-cents worth, Dennis.