Since Vanagons don't have an Accessory position on their ignition switch,
since many radios draw some current when off,
since I often want radio on but ignition off,

I always put in a little on-off switch for battery voltage supply to the
radio.
sure..one looses the stored radio stations each time, not too big a deal.

another way is to use the 'key-in buzzer' circuit in the ignition switch
wiring ..
that way you need the key inserted for radio B+ but the ignition doesn't
have to be on,
and you don't have to add a switch somewhere.

scott
On 9/1/2015 3:08 AM, Jim Felder wrote:
> About a month ago I wrote about having installed two pairs of USB ports and
> an LED voltage display in my Vanagon. The round double outlet on the dash
> took the place of my factory Eberspacher heater knob and the
> outlet-and-voltmeter combination set neatly into what was the rear ashtray.
>
> That's when I noticed a drop in voltage that would flatten the battery
> after a couple of days of being parked. Long story made very short, I
> discovered that it was my radio in standby mode that was draining the
> battery. I pulled the fuse to the radio on Saturday and this morning the
> voltage is showing 12.9, exactly where it was when I pulled the fuse.
>
> The reason that this was unknown to me all this time is that coincident
> with the addition of the USB ports the Vanagon was, except for use of my
> wife's Prius, my daily driver had been the Vanagon. When I got a TDI Jetta
> the Vanagon started sitting for days or a week at a time, and that's when
> the problem showed up.
>
> I could wire the radio to the switched 12v circuit that no doubt came with
> it, but then I would have to have the key on to listen to music while
> camping. Is anyone using a switch on the circuit, and if so how was it done
> and how does it work out for you?
>
> Jim
>