Below are pages from the 1955 Cub operator's manual showing which post on the generator is the A, and which is the F.
It looks like the post to the left side of the Cub is the A post. The A post on the gen is usually marked Gen on the voltage regulator.
The center pic shows the wiring routing also.
http://farmallcub.com/rudi_cub/www.clea ... age-38.jpg
The page below tells what the numbers on the 1st page are, and has a pic with the hood off, showing where the voltage regulator is.
http://farmallcub.com/rudi_cub/www.clea ... age-39.jpg
IH began using the voltage regulator electrical system on Cubs during 1950, at Cub serial number 115403.
They had the 3 brush gen up to 1962, like Jim said on page 1 of this post.
The info is in the Cub parts manual.
Someone was saying there is info online saying they only used the 3 brush gen with a Cutout, or Relay, IH called it. That is not what the Cub parts manuals say.
The points in the voltage regulator can get burned over time, then sometimes the reg won't work.
You can file them, and clean them. Run a clean rag through them after filing them, and clean all filings off of them.
Sometimes the reg will work again, and sometimes it won't.
One coil of wire and set of points controls the voltage output of the gen. Sometimes the reg needs adjusting to put out more, or less voltage.
It is the set of points that is always closed.
The spring that holds the points closed needs more tension to increase the voltage output.
There is usually an adjustment for it.
The other set of points turns the charging system on and off.
The points should be open when the engine is off.
Below is a pic of a Cub voltage regulator.
The coil of wire with the points that control the voltage output are on the left, notice the reg is facing with the 1 wire post toward the camera, the 3 posts are on the other side or the reg.
I don't know if all brands of regulators are made the same.
There may be an adjustment screw on the other side, away from the camera, I don't know how every brand is made.
I have bent the metal mounting at the bottom of the spring, where the pencil is pointing.
More tension on the spring increases the voltage output, on the brand of reg I have anyway.
It only takes a tiny amount of bending to change the voltage output.
