Lights on a positive grd.??

The socket is wired so that the outside of the bulb is grounded ,and the other side of the filament is connected to the centre terminal .

To have a +ve or -ve ground battery only makes the electrons flow the opposite way through the wires . And they always flow from the -ve post through the wiring -to the +ve post of the batt .

Looking at this another way-- a 100 watt light bulb ,house wiring , has the current flowing both directions --first one way --then the other way --and back the first way , etc. -- changes direction 60 times per second --hence 60 cps .

The only reson for concern is the polarity or output polarity of the generator or the alternator -- the battery and gen/alt must be matched to the batt configuration ,and vice-versa

If'n you continue to run your headlight thru your ignition switch, its gonna burn out the switch contacts and then you'll wonder why you can start your engine and it quits in about 10 minutes and won't restart until tomorrow.

If'n ya feel ya just gotta idiotproof your headlights, then ya gotta wire up a load shedding RELAY that is operated by the ignition switch. Most Relays take milliamps to operate great big ol'contacts that'll handle 30 amps, which by the way, is the way modern automobiles do it anyways..... ....Dell

That's my input from an old "shadetree" mechanic.