Led headlights don’t work right with fog lights?
11-16-2018, 10:20 PM
#1
Junior Member
Thread Starter
Led headlights don’t work right with fog lights?
i installed led headlights and with the fog light relay unplugged they work perfect. If I plug the fog light relay in they do all kinds of weird stuff. Is there a different relay that I need to get for it all to work together?
11-17-2018, 05:14 PM
#2
Re: Led headlights don’t work right with fog lights?
The reason for your problem can be found in the lower lefthand area of this wiring diagram .
The foglight relay's coil gets it's ground through the high beams filaments when the low beams are on . When the high beams are on the relay's coil has +12 volts on both sides and the coil obviously won't engage . This is how GM wired it so that the foglights will work with the low beams only . What's happening is that your LEDs aren't at all happy being connected as a ground source for your foglight relay's coil .
Were this my problem to solve , if I wanted to keep the LEDs and have functional foglights , here's what I'd do ;
I'd cut the light green wire at the foglight relay at terminal "C2" leaving a few good inches of wire on the relay side of the cut wire , and I'd ground the cut wire leading from the relay , and then tape off (insulate) the other end of the wire from the harness (that was leading to the relay) . This way the LEDs will never see the relay's ground load and the foglight relay won't need the high beams for it's ground . Bonus points are that the fogs will now work in either low or high beam , which is how I personally like them to work (I've done the green wire modification on past cars even without the LED headlight problem simply because I don't like my fogs going off when the high beams go on) .
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Buddy (01-31-2021)
11-17-2018, 07:30 PM
#3
Junior Member
Thread Starter
Re: Led headlights don’t work right with fog lights?
Orangebird thank you very much. I have been beating my head against the wall with this. The diagram is blurry when I bring it up. C2 is a terminal at the actual relay? I would go out and look but the car at a buddy’s house. I will go do the ground trick you are talking about in the morning. Thank you for your help.
11-19-2018, 03:54 PM
#4
Junior Member
Thread Starter
Re: Led headlights don’t work right with fog lights?
Orangebird you were spot on. I grounded the light green wire and everything works like a champ. Thank you for your help.
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