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Wiring fog lights in line with high beams?

Sir Psycho

holstrich 2.0
Sep 27, 2008
Austin TX
I have ecode headlights with integrated fog lights on a 940 that originally came without fogs. I don't want to go through the trouble of wiring the fogs to a switch and the fuse box so I was thinking about splicing them in with the high beams. I assume splicing them in line would half the voltage to each light. I am not great with electrics, would I need some sort of relay to get full power to each of them? Is there any reason this would not work well or a better way to do this without going straight to the battery or fuse block?
Personally, I'd wire up relays for each pair of lights, in a do it properly and do it once fashion.

Fog lights are really only for use with parking lights and low beams, and not particularly useful with high beam. Actually the 940 e-code fog lights are not particularly useful anyway.

You won't cut voltage by half by splicing into the wire, however running that much current though such a thin wire is a bad idea and also may blow fuses.

Remember those lights have a H4 60/55w bulb for high and low beam, a 55w H3 for fog lights, and a 55w H3 for additional high beam.
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High beams defeat the purpose of fog lights, wire them in sequence with the low beams if you must. Use the power from the low beams to trigger a relay that turns on the fogs to prevent electrical fires. High beams in fog turn the world into a white cloud that you cannot see through. Best thing to do with thick fog is get off the road, it can be worse than white out snow conditions.
In some places it is not legal to run fog lights in conjunction with high beams.

At any rate, the power needs of fog lights should not be added to another lighting circuit as it will/may cause an overload (flamb?).

The aux lights should have their own fused power source from the battery and use a relay to switch that power.
Are you sure there's no wiring behind the bumper for any foglights? I found my car to have the wiring for both the bumper and integrated fogs. Check behind your switch blanks and your rear fog switch. If it has more pins than the switch, then you may already have fog electrics! That's how I found mine, hahaha.