I found a 3 pos switch on:off:on, and wired the common to the radio
power lead. One hot side I wired to the existing radio power which is
switched by the ignition, the other hot side came from my accessory
battery.  SO now the radio can run off ignition sw control (stock), be
turned off, or run off the accessory battery. I believe Gowesty has a
kit for this.
Jon

On 9/1/2015 7:08 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