I have a similar switch setup on my 1985. I don't know what the accessories switches do either. If you find out please email me or post it. Thanks for the post

I'm gradually solving the mysteries of Barth ownership. I have identified the purpose of most of my mystery switches. However getting them all to work is another story.

As Mogan David suggested not all of my Accessory switches are wired to anything. I loosened the dash panel and peeked behind and two of the three have no wires. The one that is wired I believe controls the dash mounted fans. Neither seems to work at the moment. Anyone with dash mounted fans care to share how they operate and whether they use one or two switches?

The more I explore the more impressed I become of the coaches design. The auxiliary heater is especially useful for me as my coach, apparently like many others, has had heater core issues and currently has the core bypassed so there is no heat from the dash. The system that uses the engine coolant to heat the hot water holding tank while driving has a separate valved Y to divert the coolant through a radiator under a rear closet. A rocker switch on my dash drives a two speed fan that blows heated air to a vent by the entry stairs. A separate heater hose directs hot air to the fresh water holding tank.

The two dash fans (on my coach) are controlled by one rocker switch. Center=off Top in=high speed Bottom in= slow speed....................

Jim, check under dash behind brake for an aux. fuse panel (glass fuses). this is where my power for my fans come from.

Doorman