12V one wire alternators

I put a 1 wire on my AC WC in 1998 and havent had a single problem. I run 2 batteries for a Western snowplow.

Bobs directions are just as easy and it will save you having to put a self exciting regulator in. I just happened to have one already so I just used it.

Rick

They are EASY to hook up, are cheaper, and more readily available, and will begin to charge at lower RPM"s than the GOOFY "one-wire" units.

All you need is a few simple connections, as shown here, and a diode, as shown, or an "idiot light" using a #194 lamp.

The diode in the lead to the alternator"s #1 "switched excite" terminal, OR the light bulb, spliced into the same wire, are DIRECT substitutes for each other.

(If using an "idiot light" the diode will NOT be spliced into the harness, as shown, instead, the same wire will lead back to the switchbox, and be connected to the "idiot light", and the other terminal of the "idiot light" will connected to the "switched" side of the ignition switch.)

If the tractor has a mag, you can use a 4 psi oil pressure switch in the "excite" circuit, since all the tractor would have is a "kill switch".

Linked below, are more diagrams, from Bob Melville"s site. #9 is the oil pressure switch/mag diagram.

• BobM's diagrams

Link

Ifffff the tractor has an ammeter, the alternators big output stud would wire up to the ammeters Load side terminal and I would use 10 Gauge wire. The ammeters Load side terminal is the terminal that used to wire to the BAT terminal on a Voltage Regulator or Cutout Relay and is the same terminal that feeds hot battery voltage to other loads like lights and/or ignition. The ammeters other Supply side terminal (only one wire to it) is the one that wires to the battery, often at a starter switch or solenoid where the big battery cable attaches.

If you have to convert to Negative ground the batterys - then goes to frame while its + goes to the starter switch or solenoid. Also the ammeter leads would need to be swapped and if it has a coil ignition instead of a Magneto the coil leads get swapped also.

Some one wire alternators require a higher RPM to kick in and on some theres a small trickle discharge when shes setting. Many people use the 3 wire GM 10 SI alternator instead and wire/configure it to work like a one wire.

John T