exciting the alternator on a 1989 john deere 210c backhoe

Hi,
i was just wondering if anyone knew if the alternator on an 89 210c has to be excited? I had the alternator rebuilt, then a neighbor borrowed it, he called a few days later and told me he just took the alt. to a rebuild shop because it was bad. I told him to go get it back because I just had it rebuilt. He brought it back home put it on and still no charge. So I called the shop where I had it rebuilt, they told me to excite the alternator and see what happens. I did and it started...

exciting the alternator on a 1989 john deere 210c backhoe

exciting the alternator on a 1989 john deere 210c backhoe