Fog Light Wires?

[2000volvoturbo]

Hello to all again.Can anyone give me a little help here,I am installing fogs on my 2000 Volvo s70 Glt Se now I am going to by pass the relay option and go directly to the battery to power the fogs.Thanks to this forum it has helped me a hole lot.Now I know about running the green and orange wire to the fogs but there is a second wire that is on the fog lights (or coming from the fog light),would that be a ground wire also??? I no I have to ground the switch,but the other wire on the fog lights is that also a ground??Thanks

[pkc303]

Are they new? Instructions? Could be a wire for the relay. You are going to want to do the relay option, so you don't end up with one light brighter than the other.

[BEJinFbk]

There are a number of good reasons that fog lights have relays.
And there are a ton of posts here and on other sites about
how to make them work and keep it all stock.
Have you searched them?

[fazool]

Well, I remember doing a similar thing myself once back in the day. So let me share the lesson I learned so you can benefit from it:

The fog lights (and many suchelectrical devices) consume a large amount of power. Because of that, they draw large currents to feed them. Such a large power draw needs a low resistance conductor that can handle all that current. In other words, they need a BIG wire for all those electrons.

A typical dash mounted switch is physically small and cannot connect to a large diameter wire so they run small wires. If you try to run small wires to the fog lights, they won't be able to handle the current. They will overheat and (in my prior youthful experience) catch on fire under the dashboard.


The purpose of the relay is to be a remotely controlled switch that CAN connect to bigger wires. So the small dash switch commands the relay which flips a BIG switch.

Imagine running your battery cable through a tiny little toggle switch and on to your started motor. Flip the switch and watch the flames.