I just installed one plug and play style from Competition Ltd in Michigan.
Great setup, easy to use. The wires between the lights are (I'm guessing)
12AWG or 14 AWG, their big. The battery wire I ran is 10 AWG that splits to
two smaller fusible links that go to each of the bulbs. Full price is $64
US but I got mine for $35. Some kinda discount because I bought bulbs too
maybe?
They also sell the bulbs for the H4's in different wattages and  colors for
out Vanagons.
I've been please with mine. Usual disclaimers apply.
Contact info:
800.770-5553
734.464.1458
734.878.5477
Later,

Dave & Sherrie
Williamsburg, VA
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