Another TO-20 charging system question

Stephen Ford

New User
Ok, I have searched the forums and have found some great answers but I still have some questions unaswered and some not very well understood.
First off this is a 1951 TO-20 with the factory 6v positive ground system. Generator is good and I just replaced the voltage regulator and rewired the tractor.
First question, how do you identify the field and armature terminals on the generator. There are no identifying marks on the generator body but what looks like a triangle near 1 terminal.
Second, the dash light. The shop manual shows it to be in series with the switch power side of the ignition switch and the "G" terminal of the regulator. The problem I see is that the light socket snaps into the dash of the tractor. The socket body and bulb ground are common. So in other words when I snap this socket into the dash the bulb ground side will become common with the rest of the tractor grounding system which in this case is positive and will thereby cause the bulb to stay on at all times when the key is in the on position. I hope some one can understand what I just said because I went cross-eyed writing it... Only thing I can see is if there was a plastic washer or something like it from that factory to isolate the socket from the chassis.
I have read some just bypass the light all together and tie the wires together, but I am trying to put this tractor together they way it originally was, but I am not opposed to an easier method at this point. Thanks again for the help and hope no one gets a headache after reading this.

Steve
 
The field coil is the small terminal the armature is the large one. I just checked my wiring diagrams and they are all the same as you have, I then checked the diagrams for an Alternator type and they are wired similarly. I can't check it physically because I don't have a tractor here right now....John
 
I have some questions about the ignition light. Are they still available. Is the light used in conjunction with the ammeter, or is it one or the other. mine currently has the ammeter and the empty hole for the light. which one is correct for a 51 To20?

thanks, Josh H.
 

The wiring diagram in the repair manual I am using does not show an ammeter, just the charging light. My 51 TO-20 did not have a place for it on the dash either so I am guessing the ammeter on your tractor was added.
 

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