Technical > Automotive > Need basic info on Fog lights.

reply to cchheett

Re: Need basic info on Fog lights.

"Wire the relay so that when you turn on the high beams, they go on as well. You can, and will blind people if they are on at all times."

Don't do this! It is illegal in some states to have fog and/or driving lights on at the same time as high beams. In addition, as several people pointed out, fog lights need to be aimed low to keep the fog from reflecting the light back, while high beams are aimed high.

I think most original equipment "fog lights" on SUVs are just for show.

Yes, people will need to check local laws. This is not news for advice on a forum, right?

As stated previously, I believe the OP was referring to driving lights. He said he didn't see very well at night. That would preclude 'fog' in my mind.
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I'm not anti-social, I just don't like stupid people.

reply to Paul Sweet

Strange -- Mercedes put white ones on my vehicle! Actually what makes a fog light is the pattern of the light, not the color.

My understanding is that driving lights are normally used with high beams to provide focused light down the road. Fog lights are used with low beams (in some areas people may just use fog lights, but legality depends on jurisdiction) and provide a wide beam pattern focused close to the ground with a sharp cutoff of light a couple of feet off of the ground.

With aftermarket fog lights, I think the most important factor would be to buy a set with a well engineered reflector and proper beam pattern. Then, of course, make sure to follow the instructions regards mounting them.