3 wire alternator exciter light

rcfarms

Member
Rewiring my Allis C. Has a 3 wire alternator and not sure if I need a light for the #1 alternator wire or not. I've heard both ways (yes/no) and I'm confused. Previously I had trouble with the battery running down if I didn't remove the battery ground. Although it had been converted to 12V the previously the wiring wasn't done very well. I would appreciate any help and if I do need a light would a 12V LED work? Thanks
 
Yes, you will have to have either an exciter light or a diode in order for the alternator to charge and to prevent back-feeding. I used a .99 cent indicator light from the local parts store, and even though it doesn't light up when in use, it still prevents the alternator from back-feeding and draining the battery.

Mac
 
There are a number of ways you can wire them up. You can use a light bulb or diode or a resister or you can have anther switch for the excite or you can also just shut the gas off to shut it down. All of those work and I have seen all of those used
 
Always happy to help if and when I can. I have one tractor that has a ballast resister in the excite wire and has since before I got it. I have a number of them with diodes and one that for some reason a diode does not do it so I turn the gas off and that also works just fine. I also have one with a 2 position switch. You pull the switch out to the first position to turn on the ignition. You pull it out to the 2nd position to turn on the head lights and the excite circuit
 
Yes, it will need a light (or a resistor or a diode).

The light is the easiest, and it needs to be a 2 wire socket, not a grounded base socket, and it MUST be an incandescent lamp, NOT a LED. An LED doesn't have enough resistance to excite the alternator.
 
Just wondering if I wanted a light (not the exciter light) to operate while the tractor is running then goes out when I shut the tractor off at the key switch...how would I wire that?
 
Or if you have them an O'Reilly's LOL. In my case it is O'Reilly's or auto zone and the people in the zone do not have clue
 
Or if you have them an O'Reilly's LOL. In my case it is O'Reilly's or auto zone and the people in the zone do not have clue.
By the way part #VR-1 or VR-2 is a resister that works well and that is the O'Reilly's part number
 
Old, sounds like you have a few Allis C's. I know this isn't the forum but are you familiar with the C front mounted cultivators? If so, I have a set I'm trying to install and have some questions.
 
I know very little but the mounting of cultivators on a C. I do have 2 whole Cs and 2 parts Cs on the place and one of the Cs have a fount snow plow lift and a 3 point and the other has the belly sickle bar mower
 
I prefer the lamps to a resistor or diode.

Got an 8n that will let the goo out of the coil if I forget to turn the key off after shutting off the gas letting it run dry. So the light reminds me to turn it off.

Pretty sure these are the lamps I've used.

Fred
Lamps
 
I have a Delco 3 wire on my 4020 and 3020 and combine you don?t need a light or a diode for the 10si anyway. I buy the vr plug then run the red wire to the battery and the white wire to keyed 12 volt power off the key switch.
 

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