Hang on a minute,
Before we get into overly technical solutions and talk of diode packs and such, lets look at the

problem as stated

the B+ terminal (which should have the heavy gauge cable on it to the battery) is getting hot,there are two possible causes, either the entire alternator is producing or receiving a massive current due to a fault which is exeeding the terminal`s capacity, or, (much more likely), the connection itself has a bad ( ie high resistance) connection though which the charging current is passing and producing a voltage drop.

To put it in simple terms if a terminal gets locally hot there a poor connection

at that point 99 times out of 100.

Clean the mating surfaces of the connection and replace the ring terminal (the problem may be in the crimped joint) on the end of the of the wire and it will, in all probability, cure the problem.
If not, and the wire itself is cooler the further away from the from the connection you get, the problem is probably a bad connection at the other end of the mounting stud, ie. inside the alternator. Always try the simple solutions first, they are nearly always the cheapest and very often the cause of the problem.
Good luck,
Colin.