Idea for keeping Fogs on w/Hi (SD 2008-Up)

pog · Feb 15, 2012

so i have the fog relay kit ordered. now i have been thinking of how to keep the fogs on with the hi's without getting into it rewiring stuff. i am also running retros hids. now if i tap into the HI beam power wire from the oem plug and run a wire to the power wire on the relay side (on fog kit) would this work without damaging anything? if this were to work, would there be a second the fogs would flash off/on between the lo/hi (vice versa) transtition? goal is to to keep using stock headlamp/fog switch for its purpose without fogs turning off when swtiched to hi. 08-up SD arent quite as easy as previous years to get hi/fogs to work together.

thanks

jdgleason · Feb 15, 2012

Interested in what you find out...

Zmann · Feb 15, 2012

Have you seen these

http://www.innovadd.com/bb.main.html

pog · Feb 15, 2012

yea. i really wanna keep this as simple as possible. dont wanna put out extra money just to get hi/fogs to work together. i figured since i need the fog relay kit my idea might be worth a shot. easier to tap into wires than into my wallet lol

pog · Feb 15, 2012

update. just got off the phone with todd. all is good. just gonna add a diode between the hi beam wire and the relay power line to prevent reverse current, and also add a capacitor after the diode to prevent any "off/on" effect between lo/hi transition.

pog · Feb 15, 2012

now that i think about it, the fogs will always turn on with hi's. :doh:

Zmann · Feb 15, 2012

Im sure you could figure out a rectifier diode wiring combo but the wiring might not be up to the full load of lows/highs and fogs all at once ,,

CSIPSD · Feb 15, 2012

You can just modify the switch.

Find the wire that turns the fog's on at the light switch. Then cut that wire and tap into the running light switch...

Took me a few minutes to find this post on another site, and I understand that this is for a 2001, but with some time and a test light the same thing could be done on your truck.

OBSWIZ said:
I have lots of stickies in my computer..sure helps when you can only use 2 fingers to type.

Fog switch upgrade: couple of ways..

2001. Remove the headlight switch plate and unplug the two plugs. Take a drilll bit inside the the switch and remove enogh material so that you can pull the switch out it the parking light possition. Next take the white wire with the black stripe on it and cut it. tape off the end that goes back into the wire harnes under the dash so it will not short out. Take the other end of it that goes into the plug end and tap it into the parking lights, the brown wire. Now you have fog lights when you pull the switch out in the parking light possition and you keep them when you turn on your high beams.

Or:

http://www.ssdiv.com/fogfix.html

retrosolutions · Feb 15, 2012

Zmann said:
Im sure you could figure out a rectifier diode wiring combo but the wiring might not be up to the full load of lows/highs and fogs all at once ,,

He'd using relayed harnesses, the factory wiring would only be carrying a maximum of 1A split between the 2 relays at in-rush.

retrosolutions · Feb 15, 2012

CSIPSD said:
You can just modify the switch.

Find the wire that turns the fog's on at the light switch. Then cut that wire and tap into the running light switch...

Took me a few minutes to find this post on another site, and I understand that this is for a 2001, but with some time and a test light the same thing could be done on your truck.

He's opposed to modifying the stock wiring to do the method described on ssdiv

pog · Feb 15, 2012

what about this.. hot wire form hi beams -> tap into the wire going into the fog lamp -> another wire tapping into the wire that leaves the fog switch -> tap into power triggering the relay for fogs? looked over the ssdiv way, that way makes sense too but i got a canadian truck. dont wanna start messing around with the sjb.

Worstenemy453 · Feb 15, 2012

Have you checked your local laws ?

In VA it is illegal to run fogs/highs at the same time. Make sure its cool in your state.

pog · Feb 15, 2012

Worstenemy453 said:
Have you checked your local laws ?

In VA it is illegal to run fogs/highs at the same time. Make sure its cool in your state.

i live in canada, all my night driving is down country back roads.

Zmann · Feb 16, 2012

pog said:
what about this.. hot wire form hi beams -> tap into the wire going into the fog lamp -> another wire tapping into the wire that leaves the fog switch -> tap into power triggering the relay for fogs? looked over the ssdiv way, that way makes sense too but i got a canadian truck. dont wanna start messing around with the sjb.

Not sure I semi recall the fogs are switched strange depending on what actuates them or turns them of like the ground drops out if the highs go on it's not super simple but I bet there is something out there in Google land

retrosolutions · Feb 16, 2012

Zmann said:
Not sure I semi recall the fogs are switched strange depending on what actuates them or turns them of like the ground drops out if the highs go on it's not super simple but I bet there is something out there in Google land

They are setup in a ground bias, such that when in balance (as it is with the stock bulbs in the system) the high beam circuit "takes" if you will, ground from fog circuit. So only one can be on at any given time. The methods listed prior, like that from ssdiv for example, removes the bias so the fogs and highs are switched independently of one another.

pog · Feb 16, 2012

but since im using the fog relay kit would that not give a "new" ground for the fogs to stay on with hi's, as long as the relay is still getting power to trigger it.

retrosolutions · Feb 17, 2012

pog said:
but since im using the fog relay kit would that not give a "new" ground for the fogs to stay on with hi's, as long as the relay is still getting power to trigger it.

unfortunately not in the same way you are thinking of it.