>>| ?? - Since headlight power is only available when key is on, pull out 
the
>>| rocker switch and wire the marker lights 'out' lead to the 'in' lead for 
the
>>| headlights. This should switch the side lights on in the usual manner 
via
>>| same wiring. No relays, draws current from high amp headlight section. 
 If
>>| you wanted headlights on too, jumper across the back of the rocker 
switch
>>| for them. Stalk would still do the hi/lo bit.
>
> You might want to consider adding a rely that is wired to bypass the
>switch when the engine is running and the alternator is cranking out power.
>If you ever sat with the ignition on to be able to raise and lower the 
windows
>for example (if you have power windows) or if your stereo is ignition
>controlled, or just sat there for some reason, you could deaden your 
battery
>right quick, or draw enough current for the lights that the starter might
>have a hard time cranking the engine in cold weather. If the switch is
>bypassed and not removed, you could still turn the lights on without the
>engine running if you ever needed to...

Just an idea...
 Why you don't feed the relay with the power source for the fuel pump?
The fuel pump is only powered when the ignition system sends pulses
to the fuel pump relay. You will be sure that the headlights only switched
on when the engine is running.
 Or use a second fuel pump relay and wire it up to the ignition coil port 1.
That is the same effect.

Helmut
'80 Camper