Foglights On With High Beams

pgamboa · June 7, 2017

Try a different corner within the slot.

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Ravenkeeper · June 9, 2017

How positive of a feel does your setup feel when you insert your diode? I did mine last night... pushed rather hard with needle nose pliers, and it didn't work at first when I tested it... pushed even harder until the diode "arms" bent... tested it, and it worked. Nothing ever did seem to click in past the connector or anything, so I don't necessarily have full confidence that it won't vibrate back out and stop working. Any tips?

Try a different corner within the slot.

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I had to try multiple corners on each slot, before it would finally slip in.

dbbd1 · June 25, 2017

Try a different corner within the slot.

If I had a dollar for every time I heard that...

Edited June 25, 2017 by dbbd1

pgamboa · June 26, 2017

If I had a dollar for every time I heard that...

$4? Lol. Good thing it didn't auto correct "slot".

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Spurshot · July 6, 2017

Some diodes have fat leads. Sharpen the end.

OBO · July 6, 2017

Hi everyone, just found this site, looks really good, i realize this is a GM truck site but maybe someone on here can help me with 2012 GM Acadia,does anyone know if the fog lite mod will work on this SUV,i tried putting a jumper with a diode from the fog relay to the hi beam relay, on pin 85 on both relays but it dont work, tried a number of times and i do have the diode the right way, now mind you this mod is for pickups but i thought maybe it would be the same on SUVs but maybe not. I also found someone on the Duramax forum that said their using pin 87 instead of pin 85 to do this but i dont know if i should try that. Does anyone know if the wireing is the same on a SUV and a truck.

arcasey · July 7, 2017

Hi everyone, just found this site, looks really good, i realize this is a GM truck site but maybe someone on here can help me with 2012 GM Acadia,does anyone know if the fog lite mod will work on this SUV,i tried putting a jumper with a diode from the fog relay to the hi beam relay, on pin 85 on both relays but it dont work, tried a number of times and i do have the diode the right way, now mind you this mod is for pickups but i thought maybe it would be the same on SUVs but maybe not. I also found someone on the Duramax forum that said their using pin 87 instead of pin 85 to do this but i dont know if i should try that. Does anyone know if the wireing is the same on a SUV and a truck.

Have you tried connecting the diodes to any other pins other than pin 85?

Typical wiring for 4-5 pin relays is:

Activation circuit: pins 86 & 85. Pin 86 is usually the power input from the circuit you want to activate the relay and Pin 85 typically goes to ground but it can work either way.

Power circuit: pins 30 & 87. Pin 30 is typically incoming 12V power and pin 87 would be the output.

So, if it is wired like this I would jump from pin 87 of my high beam relay to pin 86 on the fog light relay. If you have a voltmeter I would check voltages at the relay pins during different states to figure out where I needed to connect my jumper.

Almboss · July 12, 2017

What would be the best way to wire a LED light bar to the high beam? I already got the switch hooked up inside the cab and the wires ran through the fire wall and hooked up the the battery like normal, BUT I want to switch it from being powered from the battery to power from the high beams when they turn on.

paauto · July 12, 2017

What would be the best way to wire a LED light bar to the high beam? I already got the switch hooked up inside the cab and the wires ran through the fire wall and hooked up the the battery like normal, BUT I want to switch it from being powered from the battery to power from the high beams when they turn on.

One way would be tap into the high beam circuit under the hood at one of the lights. Then run that wire thru the firewall to your switch and then back out the firewall to a relay. That way when the high beams are on and your switch is on, it would activate the relay and power the light bar. Sounds like you've already got the hard part done - running the wires thru the firewall and installing the switch. You just need to re-wire one end of the loop to tap into the high beams. The other end goes to the relay to turn it on/off.

Almboss · July 14, 2017

What would be the best connector to tap into the wire? Had the relay for the light bar get corroded once, wouldnt want that to happen with the wiring on the head lights. The white wire on the head light connector is the high beam?

arcasey · July 14, 2017

What would be the best connector to tap into the wire? Had the relay for the light bar get corroded once, wouldnt want that to happen with the wiring on the head lights. The white wire on the head light connector is the high beam?

Quick Splice Wire Connector:

This should be all you need. I would get some that are weatherproof just to be on the safe side. They don't cost that much more.

According to the GM Upfitter guide the high beam wire looks to be "white" or "light blue", unless I'm reading the diagram wrong. Here's a link so you can look at it for yourself:

https://www.gmupfitter.com/files/media/photo/578/Sierra_Silverado_Electrical_Body_Builders_Manual_Service_Manual_2015_en_US.pdf

Should be on page 14 of 896

ereid74 · July 24, 2017

I apologize in advance but I cant find anything in this thread that pertains to me. I have a 2017 and I can't get this to work. Does anyone know what pin I should be looking for?

Thanks

OmniCamaro · August 3, 2017

I apologize in advance but I cant find anything in this thread that pertains to me. I have a 2017 and I can't get this to work. Does anyone know what pin I should be looking for?

Thanks

I also have a 2017 and all works as it should. Be sure the truck is running and the headlights are on. If it's daytime cover the sensor on the dash. Also, the diodes can be in the hole and not making contact. I used a small diameter pick to find the best corner to push the diode into and also opened it up a tad with the pick. The diodes go in quite a ways.