Fog lights auto on with low beams?
- Thread starter Ant
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
dropmech
Puddle Pirate
You'll probably have to run another diode from the low beam to the fogs in the fuse box. The fogs should be coming on automatically if you go to highs as of now.
Yea they come on now with the highs and I'm thinking a diode from fogs to low beam with the gray band on the low side but not sure which prong
I haven't had the time to try yet maybe try soon though
Gotcha. Off the top of your head to you know what kind of diode to use? Ive got a few laying around and was wondering if one would work. And you just hook it up to the positive low and positive fog side of the fuses right? Wish I would paid more attention to that electrical class in high school lol.
polobuds
Full Access Member
should be 85 on the relay map. I think 03-06 tahoes/gmc have same fuse box setup, but I'm not 100% sure on that. I just did the 4 hi mod with diode in low and high #85 spot. I had an extra diode and did the 6 hi mod by doing what you just said...diode in high and fog relay in 85 spot with gray part of diode facing high beam relay. Had it for a while then took off 6 hi because I have HIDS in fogs and dont like them turning off and on frequently. Im afraid I'll burn HID bulbs quicker, plus with the 4 hi, i have plenty of light. Although i was considering wiring it up for fogs and lows like you.
Pics always help
diode connects 85 low relay to 85 hi relay. if you want fogs to come on with lows, then connect another diode from 85 low relay to 85 fog relay (fog relay is the black relay in next pic, bottom left corner)
pic showing diode connecting from low relay to hi relay in the 85 spot. It's a tight fit but make sure diode is touching metal peg for on the relay. It may help to remove the DRL relay to get to the low relay
results
good luck!
Pics always help
diode connects 85 low relay to 85 hi relay. if you want fogs to come on with lows, then connect another diode from 85 low relay to 85 fog relay (fog relay is the black relay in next pic, bottom left corner)
pic showing diode connecting from low relay to hi relay in the 85 spot. It's a tight fit but make sure diode is touching metal peg for on the relay. It may help to remove the DRL relay to get to the low relay
results
good luck!
Last edited:
BananaHANDS
Full Access Member
Okay, I'm gonna be that guy. Just a heads up it's illegal in most states to use fog lights except in inclement weather(Rain, Sleet, Snow, or Fog). Most of the time you won't get a ticket but if you're out and it's late at night cops WILL pull you over just to see if you're up to no good. They refer to these types of stops as 'freebies' because they don't have to wait until you actually commit a moving violation. I work in detention and have booked in several people who had an old traffic warrant that they'd forgotten about and a cop stopped them for something silly and now they're sitting in jail with their car impounded because the cop is required by law to bring you in once he finds out you have a warrant.
Now don't get me wrong I myself plan to do the 6 hi mod in the near future but w/ it only being active with the hi beam switch you are less likely to happen upon a cop and not have the ability to turn them off. Sorry I drifted toward a soap box there for a bit, but I feel like like you guys should be wary of this cuz even tho it's cool it's really not that difficult to hit a button, and keep yourself from being harassed by the police. My point is it's a good idea to retain in-cab control over your fog lights just in case. that being said what if you were to wire toggle switch into your dash that way while it's flipped they'll come on with your parking lights automatically but you can also decide not to use it.
Now don't get me wrong I myself plan to do the 6 hi mod in the near future but w/ it only being active with the hi beam switch you are less likely to happen upon a cop and not have the ability to turn them off. Sorry I drifted toward a soap box there for a bit, but I feel like like you guys should be wary of this cuz even tho it's cool it's really not that difficult to hit a button, and keep yourself from being harassed by the police. My point is it's a good idea to retain in-cab control over your fog lights just in case. that being said what if you were to wire toggle switch into your dash that way while it's flipped they'll come on with your parking lights automatically but you can also decide not to use it.
I dont know of any states that say you cant use your fogs anytime. I believe some of the newer model cars will have the fogs come on when lows are on even.
It is illegal to have more than 4 forward facing driving lights on your rig though and could be a freebie. The only time you would have more than 4 is on a dark ass highway though and you should see anyone coming from a ways off.
BananaHANDS
Full Access Member
The point of my post was that it's a good idea to be able to turn off your fogs without too much trouble. Also all vehicle manufacturers have some switch to operate the fog lights, and don't default to on any time the headlights are on.
