My Fogs Work With The Hi Beams! Do Yours!

chuck16 · October 21, 2009

Looks good. That's one thing across all manufacturers that ticks me off about Fog lights. On every vehicle I've owned I've always run Fog lights separate from the main Headlight system. I've always tapped them off a switched ignition point with a relay and separate switch. That way I can have them on whenever I want. The trouble for me was finding a pair that were effective and fit in the stock 99 holes.

The other mod I'd like to do is have my DRL's come on with my Park lights but, I haven't got that far yet...

tekkitan · October 31, 2009

Yeah i know there is a funtional purpose to this mod.. I live in the middle of nowhere and i see deer on the road daily...

But really how often do you see deer walkin through the city

I just like to stir the pot lol

I know this is old but it isn't just for deer. Plus, just because someone lives in Las Vegas doesn't mean they live on the strip

Also there are deer all over the place here where I am in Cleveland. They roam into the suburbs and even into Downtown Cleveland on occasion. They get a bit more daring when looking for food, etc ;)

tekkitan · October 31, 2009

Looks good. That's one thing across all manufacturers that ticks me off about Fog lights. On every vehicle I've owned I've always run Fog lights separate from the main Headlight system. I've always tapped them off a switched ignition point with a relay and separate switch. That way I can have them on whenever I want. The trouble for me was finding a pair that were effective and fit in the stock 99 holes.

The other mod I'd like to do is have my DRL's come on with my Park lights but, I haven't got that far yet...

I had a 2003 Ranger before my Tahoe. The one thing I loved was that if I turned on the foglights and turned off the truck, they would still be turned on when starting the truck later. Wish Chevy did that...

pm26 · October 31, 2009

I believe that modifying the fog light to stay on with high beams is illegal - check with your state. Seems like a useless mod to me anyway. If you want extra illumination, how about a pair of good auxiliary driving lights?

700 sportsman · October 31, 2009

I believe that modifying the fog light to stay on with high beams is illegal - check with your state. Seems like a useless mod to me anyway. If you want extra illumination, how about a pair of good auxiliary driving lights?

Even if they are illegal, how would the cops know, since you not going to pass a person with you high beams on anyway, and with deer, who knows what else out in the country, I thin it is and EXTREMELY useful for country drivers

also, why would auxillary driving lights be any different than this mod?

blue dave · October 31, 2009

I do not consider these "fog" lights. I use mine as auxiliary lights. I had put higher wattage bulbs in my stock housings but that caused the plastic lens to melt. I then put in aftermarket driving lights that fit the round holes almost perfectly and used the stock mounting brackets.

They are brighter than my low beams. I have a relay that powers them right from the battery whenever my parking lights are on. I can kill my regular lights and drive with just the auxiliary lights if I want.

Wired this way they are always on whenever my lights are on. I also wired my low beams to stay on when my high beams are on. If someone high beams me they get all six lights from me and they shut their high beams off very quickly!

The best part is the long and wide lighting coverage that I get on deserted roads with all six lights on.

Johnson8537 · November 2, 2009

All right everyone. I got it done. I used 1n4005 diode from radio shack soldered some extra wire onto the diode to make it long enough. From the pictures below you can see how it was done. I went from the 85 pin on the headlamp relay to the 85 pin on the fog relay. Now anytime the headlights are on the fogs automatically are on. I dont have to push the button to turn them on anymore.

Ok i have a question for you... I assue the headlight relay is powering the foglight relay correct?

If so could a person run a wire off the 85 Pin on the foglight relay to a keyed 12V to gain access to run the fogs anytime the vehicle was on?? As in DTRL??? they would also work with lows and highs this way if I am understanding how you did yours?

You would also be able to turn them off at the switch if needed i would assume??

blue dave · November 2, 2009

Johnson,

No, the headlight relay is not "powering" the fog light relay. By connecting pin 85 of both relays together they are simply "sharing" the headlight relay coil signal.

The diode makes sure that they share only the headlight relay coil signal and that the fog light relay coil signal can not feed the headlight relay coil (think of a diode as a one way check valve for electricity).

If you ran a wire right from a switched 12V source to pin 85 of the fog lamp relay as you are suggesting, then the fog lamp relay coil would be energized whenever the ignition was on (day & night). Why would you want to do this?

The answer to your question about being able to still turn them off with the push button is no. If you energized pin 85 of the fog lamp relay with an ignition switched 12V signal then nothing could shut them off except for the ignition switch.

Johnson8537 · November 2, 2009

Johnson,

No, the headlight relay is not "powering" the fog light relay. By connecting pin 85 of both relays together they are simply "sharing" the headlight relay coil signal.

The diode makes sure that they share only the headlight relay coil signal and that the fog light relay coil signal can not feed the headlight relay coil (think of a diode as a one way check valve for electricity).

If you ran a wire right from a switched 12V source to pin 85 of the fog lamp relay as you are suggesting, then the fog lamp relay coil would be energized whenever the ignition was on (day & night). Why would you want to do this?

The answer to your question about being able to still turn them off with the push button is no. If you energized pin 85 of the fog lamp relay with an ignition switched 12V signal then nothing could shut them off except for the ignition switch.

Got ya... Thanks

On my old tacoma (06) I could power one of the relay pins and then the fogs could be turned on or off with the dash switch as long as the key was on. I chose to use the parking lamp signal as my 12v inplace of a keyed 12v so that they would only be on with my parking lights on. ( but would stay on with my lows and highs.) if I left my parking lights on i could use them at DTRLs

Any idea why the switch is no longer active with this mod??

blue dave · November 2, 2009

Johnson,

No, the headlight relay is not "powering" the fog light relay. By connecting pin 85 of both relays together they are simply "sharing" the headlight relay coil signal.

The diode makes sure that they share only the headlight relay coil signal and that the fog light relay coil signal can not feed the headlight relay coil (think of a diode as a one way check valve for electricity).

If you ran a wire right from a switched 12V source to pin 85 of the fog lamp relay as you are suggesting, then the fog lamp relay coil would be energized whenever the ignition was on (day & night). Why would you want to do this?

The answer to your question about being able to still turn them off with the push button is no. If you energized pin 85 of the fog lamp relay with an ignition switched 12V signal then nothing could shut them off except for the ignition switch.

Got ya... Thanks

On my old tacoma (06) I could power one of the relay pins and then the fogs could be turned on or off with the dash switch as long as the key was on. I chose to use the parking lamp signal as my 12v inplace of a keyed 12v so that they would only be on with my parking lights on. ( but would stay on with my lows and highs.) if I left my parking lights on i could use them at DTRLs

Any idea why the switch is no longer active with this mod??

The push button fog lamp switch is active with the diode mod as originally discussed as long as the headlamps are off. You can turn on and off the fog lamps just the same as before the mod with the headlamps off.

However with the headlamps on, the signal from the push button switch is "over ridden" by the signal from the headlamp circuit. Therefore when the headlamps are on, you can not shut off the fog lamps with the push button.

With your idea of connecting an ignition switched 12V to the fog lamp relay coil then the push button switch becomes completely useless. Your fog lamps would be on whenever the ignition is on (day and night). I am still not sure why anyone would want that.

My 02 Denali is too old to have the same relay set-up shown in this example. As I said earlier, I put in aftermarket round auxilary lights that are fed from an aftermarket relay which is controlled by my parking lamp circuit.

sic lsx · August 29, 2010

I turn my day time running lights off as soon a i turn my on during day. I see people with hids and fogs on all the time during day lol

pistonslap · August 29, 2010

I believe that modifying the fog light to stay on with high beams is illegal - check with your state. Seems like a useless mod to me anyway. If you want extra illumination, how about a pair of good auxiliary driving lights?

One reason to go this route is because that in certain areas (B.C. would be one)) driving lights must be covered while driving on any highway.

[email protected] · August 29, 2010

To answer the question this thread imposes, YES.

rob6773 · August 30, 2010

I am tempted to do this but was told years ago the four bulb thing was actually a federal rule. I think the previous owner put brighter bulbs in my fogs because they work great. I find with the very wide beam they project I can see the sides of the road which helps me see pets and kids before the stupidly cross the road with me coming.