Safari Motorcoach (SMC) bought Harney in 1996. The wiring diagram may be the same or similar to other SMC models for 1998-1999.
I don't know this for sure, but I doubt that the Harney coaches where using a "Harney specific" wiring layout by then. Look at the 1999 SMC diagrams and see if those look close to what your Coach has.
I have a link to wiring diagrams in my signature line below.
Go to the folder "1984-1999 Wiring Diagrams" then to the "1994-1998 Safari" folder. Download anything you want.
If anyone sends you a more specific/correct wiring diagram for your Harney, send me a copy and I'll add it my collection for the next guy.