I use that switch to power up my stereo.  The "Ign" input on my stereo only
took a few milliamps when I measured it, as most of the power comes from
the "Batt" input.  This way I can power up the stereo without leaving the
key on, or adding another switch somewhere.  If you'd like to do the same,
confirm first that your stereo doesn't draw significant current from the
"Ign" input.

The wire going to the lovely chime was snipped, and one side is now
connected to the stereo, and the other side connected to the parking lamp
circuit.  So now with one change I've gained a headlights-on reminder and a
way to turn my stereo on.

Back on topic, I would think a strategically placed diode somewhere would
keep the relay from staying on with the ignition off.  If that is not
possible perhaps the brute force method of putting an additional load
resistor across the relay's winding would do it.

Powering the engine with just the key in is dangerous.  Consider this
scenario which has happened to me before:  Going down a large hill my
throttle cable was frozen with ice at part throttle.  I was able to leave
it in gear and turn the key off, while maintaining all normal functions,
until I was able to find a pull-out.  If I would have needed to remove the
key, my steering would lock, and I would end up over the hill.  The other
option would be to pop it in neutral, but then the engine would be bouncing
off the rev-limiter.

Ryan

On Fri, Jan 25, 2013 at 9:44 AM, neil n <musomuso@gmail.com> wrote:

> It's been so long since I've had the key reminder buzzer installed.
> IIRC, the Su switch closes when the key is inserted in the tumbler.
>
> I can see how using Su to turn ignition would be a poor solution.
>
> Neil.
>
> On Thu, Jan 24, 2013 at 7:30 PM, David Beierl <dbeierl@attglobal.net>
> wrote:
>
> > At 09:47 PM 1/24/2013, neil n wrote:
>
>
> > Mechanically it's a horrible Kluge and I wouldn't put any significant
> load
> > on it, but a relay should be fine.
>
>
>
> --
> Neil n
>
> 65 kb image Myford Ready For Assembly  http://tinyurl.com/64sx4rp
>
> '88 Slate Blue Westy to be named.
>
> '81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/
>
> Vanagon VAG Gas I4/VR Swap Google Group:
>
>
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
>