Rectifier Location on a John Deere LA-135 LE

[SandburRanch]

Needing to test the rectifier because of alternator not charging. According to one source it is a metal box with 4 wire tabs but where it is located on the tractor is the question. One source says the operator's manual shows - not so.

I've searched for a on line service manual but struck out there too. Thanks for any help.