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Re: Re[2]: more lighting questio

Bob D'Amato said:

>> By switching ground, you always have a 'hot' lead at the relay. 

True, but you always have a hot lead at the relay anyway--the power circuit
you're using the relay to switch!

I think the point of switching ground on a relay was to eliminate an extra
12v+ wire through the firewall.  If the wire shorts and is the relay ground,
it simply closes the relay (turns on lights, here).  If the wire is 12v+ and
shorts, it blows a fuse somewhere (probably the original headlight circuit
fuse) or worse, burns out the headlight switch.

As to always switching the hot side, that's true/required per NEC for 110vac.