Mike Clarke wrote:
On Sat, 14 Apr 2012 13:18:50 +0100
John Williamson wrote:

In town, using dipped beams, the load is more like 150W,
anyway. You'll only use 400W in a situation where you are driving in
foggy conditions or using four high power halogen main beam lights.

How can foggy conditions result in so much more load? A pair of front
foglamps will be the same power as a pair of dipped headlamps and the
rear foglamps will only add 21w each which will only push it up to
about 200w total

You've got 200W minimum at the front, due to the dipped headlamps *and*
foglamps being on, then add the 42W drawn by the high intensity rear
lamps, plus at least 42W for brake lights and the same for indicators,
when they're being used. Plus, of course, at least 24W for side and tail
lights, not forgetting the side marker lights fitted to some cars. I was
giving maximum loads, not average ones.

Four bright halogen main beam lights are 350W just on their own.

--
Tciao for Now!

John.