The easiest way to find out the resistance of
components in the low-beam headlight curcuit is to
measure the voltage drop at various places in the
circuit. I originally found that I had .7 volt
difference between the fuse block supply voltage and
the headlamp terminal when of the headlights were on.
0.6 volts of that drop were in the headlight switch
itself. After I installed a headlight relay, I had 0.1
voltage drop between the fuse block and the headlamp
terminal.

I saw less than 0.1 vdc difference between the fuse
block and the main battery so adding more capacity
between those two points or running battery voltage
directly to the headlight relay didn't make much
sense.

I don't see any value in installing larger wires to
the headlamps. Currently, from the headlight switch to
the headlamp, each low beam has its own 14 ga. wire,
its own fuse on the fuse panel and its own contact
inside the dimmer switch. The only reason I see for
increasing the size of the wiring is if you are using
much higher wattage low-beam lamps (+120 watt) and are
constantly blowing the stock 10-amp fuses.

You would be better served adding additional wire
between the battery/alternator and the fuse blocks,
but again, check with a voltmeter first to see how
much of a gain you will actually see. I didn't test
mine with the heater blower on, but I very rarely use
the heater blower.

Good luck,

=====
TJ Hannink
Goldibox - 1987 Vanagon Camper, Wolfsburg Edition
Winter Park, Florida
http://home.earthlink.net/~tjhannink/
http://groups.yahoo.com/group/wolfsburg_campers
http://photos.yahoo.com/tjhannink [Vanagon] Album

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