Joey, to add a little to Charlie's photo, here's some info from a really OLD post:
<blockquote><hr size=0><!-quote-!><font size=1>
quote:</font>
"By Kmcgiver (Kmcgiver) on Sunday, November 28, 1999 - 10:53 pm:
To Mark Huffman and all: Good Point
Regulators have varied over the years. I would never go by any pic.
Your best bet is to remove the wire and look and see what the terminal says.
BAT, F, GRD, GEN. There are two different part numbers listed for the regulators and
they will interchange. There is a Terminal "L" on a 121577-C1 on the Orig and such
the only thing it did was provide power to the ign coil. The 545130-R92 used on 149,s
and the like only have four terminals. To use one of the newer style on the older
tractor all one has to do is connet the wire that went to the "L" post on the reulator
to the battery side of the starter sole.
To use a old style reg on a newer tractor don't
hook anything to the "L" post. Never know what people like me have done in the past
I have a 100 right now with the later style reg. "<!-/quote-!><hr size=0></blockquote>
<font size="-1">The post quoted above was primarily written as info to connect up a 3 terminal style regulator in a tractor that originally had a 4 terminal regulator. Rather than connecting a 4 terminal regulator into a tractor that originally had a 3 terminal regulator like you are doing. However, note the text that I made bold. And, here's additional info that forum member Roland Bedell compiled. Hope this helps.</font>