It is also illegal to show a white light to the rear in most states
according to their Vehcile Code.

For back-up light systems with aswitch on the dash..
I suppose if it's bright enough and one looks in the rear view mirrors
one would notice if it was left on while driving ..
otherwise there's a medium chance that with a manual switch back-up
light system the driver will forget it's on someday, driving merily down
the highway. Could get a ticket that way .

On 2/18/2013 4:18 PM, David Beierl wrote:
> At 07:09 PM 2/18/2013, MICHAEL H wrote:
>>  I like the idea of a switched 3rd light for tail-gaters and/or
>> high beamers. so, David, with an `85 GL, auto. can the existing
>> switch gear and wiring tolerate 3 LED lights ?
>
> Check the wattage or current ratings.  The original setup is
> switching four to four and a half amps, basically.
>
> However I *seriously* warn you against even thinking about using
> bright lights on the back for aggressive purposes.  That's how people
> get shot.  I have myself had a pistol pointed at me for giving a
> high-beam overtaker a dose of my own high beams after he passed, back
> in 1972.  He dropped back and aimed his piece, and I took rapid
> evasive action.  I've never forgotten that lesson.
>
> Yours,
> David
>