horn help needed

The horn on a friend's TR6 suddenly stopped working. He needs it for self 
defense while driving his car to work in in Chicago. My Bentley manual 
(which has taught me several new ways to cuss) does not show the relay in 
the wiring diagram. I don't have a Dan Masters book, but I promise to buy 
one. Meanwhile, could someone please tell me the destination of each wire 
on the horn relay? Thanks in advance.

uncle jack