Auto Fog lights on.

Dali555 · January 3, 2020

4 minutes ago, jlong1984 said:

I don't want my fogs on all the time. The fogs do come on and go off with the high beams.

With mine, if I have the fogs on, it disables the auto high beams

jlong1984 · January 3, 2020

21 minutes ago, Dali555 said:

With mine, if I have the fogs on, it disables the auto high beams

That's probably true. I have the Intellibeam/auto high beams disabled in my truck. They are useless and come on way too often for my liking.

Londart2020 · January 3, 2020

23 minutes ago, Dali555 said:

With mine, if I have the fogs on, it disables the auto high beams

Not for me, I wonder why that happens for you??

Dali555 · January 3, 2020

53 minutes ago, Londart2020 said:

Not for me, I wonder why that happens for you??

I wish I knew...

cdh7917 · January 3, 2020

Fog lights are meant to light up close, and down low. The reasoning behind your Intellibeam not working is because the truck has figured the driver has made a decision that by turning on the fog lights, the conditions warrant them - fog, heavy rain, snow. The truck is programmed that when fogs are on, high beams aren't helpful and could be a safety issue - feedback from high beams during heavy snow can be pretty significant.

On my 2020 HD, I had the fogs jumped using a diode to come on when the high beams came on. If I manually turned them on, the Intellibeam was disabled too, so that meant no fogs during low beam unless I never wanted to use Intellibeam.

To get around this, I moved my diode for the fogs from the high beams to the running lights. Now, any time my lights come on, my fog lights come on. Intellibeam still works as designed and I get fog lights on with both low and high beams. I live in the country and it's not uncommon to spend a good amount of time driving unlit roads through the Rockies. I'll take all the light I can get.

Dali555 · January 3, 2020

2 minutes ago, cdh7917 said:

Fog lights are meant to light up close, and down low. The reasoning behind your Intellibeam not working is because the truck has figured the driver has made a decision that by turning on the fog lights, the conditions warrant them - fog, heavy rain, snow. The truck is programmed that when fogs are on, high beams aren't helpful and could be a safety issue - feedback from high beams during heavy snow can be pretty significant.

On my 2020 HD, I had the fogs jumped using a diode to come on when the high beams came on. If I manually turned them on, the Intellibeam was disabled too, so that meant no fogs during low beam unless I never wanted to use Intellibeam.

To get around this, I moved my diode for the fogs from the high beams to the running lights. Now, any time my lights come on, my fog lights come on. Intellibeam still works as designed and I get fog lights on with both low and high beams. I live in the country and it's not uncommon to spend a good amount of time driving unlit roads through the Rockies. I'll take all the light I can get.

Nice explanation! Do you have a write up somewhere on this site I can see how you jumped it to get them to come on with the low beams? I too drive a lot of unlit roads in CT and I’d like all the light I can get as well....

cdh7917 · January 3, 2020

39 minutes ago, Dali555 said:

Nice explanation! Do you have a write up somewhere on this site I can see how you jumped it to get them to come on with the low beams? I too drive a lot of unlit roads in CT and I’d like all the light I can get as well....

This thread should help you. You can go the route of Boost Auto and pay ~$20 or spend a few bucks for twenty diodes from Amazon.

The beginning of the thread shows the wire schematic for the brown plug. Instead of using pin 18 for the high beams, I believe I picked up power from pin 22, which is the Park Lamp Relay Control.

When doing this, the diode is wedged in the back of the plug. They're directional, allowing current to flow only one way. This allows the parking lights to trigger/power the fog relay, thus turning them on.

The easiest way I have found is to take the diode and nip the ends off with wire cutters so they're pointed. Then you can use some tiny needlenose pliers to get it inserted into each pin slot as needed. It sound hard, but it's not at all. You'll want a flashlight/headlamp so you can see what you're doing though. It's dark behind that kick panel on the drivers side.

Edited January 3, 2020 by cdh7917

Londart2020 · January 3, 2020

1 minute ago, cdh7917 said:

This thread should help you. You can go the route of Boost Auto and pay ~$20 or spend a few bucks for twenty diodes from Amazon.

The beginning of the thread shows the wire schematic for the brown plug. Instead of using pin 18 for the high beams, I believe I picked up power from pin 22, which is the Park Lamp Relay Control.

I got the Boost Auto, super easy.. Well worth the $20 to not have to make the jumper, and its all clean looking.

cdh7917 · January 3, 2020

3 minutes ago, Londart2020 said:

I got the Boost Auto, super easy.. Well worth the $20 to not have to make the jumper, and its all clean looking.

It is clean for sure. I'm just personally not a fan of the vampire taps on the wires, but that's just me.

The diode can be pulled out in seconds, and there is no indication it was ever there. Vampire taps will leave nicks in the insulation of the wires they were used on.

As they say, there's more than one way to skin this cat!

Edited January 3, 2020 by cdh7917

Dali555 · January 3, 2020

8 minutes ago, cdh7917 said:

This thread should help you. You can go the route of Boost Auto and pay ~$20 or spend a few bucks for twenty diodes from Amazon.

The beginning of the thread shows the wire schematic for the brown plug. Instead of using pin 18 for the high beams, I believe I picked up power from pin 22, which is the Park Lamp Relay Control.

When doing this, the diode is wedged in the back of the plug. They're directional, allowing current to flow only one way. This allows the parking lights to trigger/power the fog relay, thus turning them on.

The easiest way I have found is to take the diode and nip the ends off with wire cutters so they're pointed. Then you can use some tiny needlenose pliers to get it inserted into each pin slot as needed. It sound hard, but it's not at all. You'll want a flashlight/headlamp so you can see what you're doing though. It's dark behind that kick panel on the drivers side.

Great! Thank you!

Ravenkeeper · January 4, 2020

14 hours ago, Dali555 said:

I don't understand why they just don't come on with the auto lights and turn off when the highs come on automatically and then turn back on when the highs turn off.... is that so hard to do? Does it cause some sort of problem for GMC/Chevy?

My 93 & 99 Grand Am's were able to turn the fogs on and not have to worry about turning them on again when I get back into them.

Ravenkeeper · January 4, 2020

7 hours ago, jlong1984 said:

That's probably true. I have the Intellibeam/auto high beams disabled in my truck. They are useless and come on way too often for my liking.

Mine drop for no reason. I have been the only one in the middle of Rosamond Dry Lake, traveling home after work and getting gas (on Edwards AFB), and my "Intellibeam" Highs would drop back to lows. A few of those times, they would remain off until I turned onto my street. These new LED stop lights will cause them to turn off too. Wish I could permanently disable the Intellibeams, daughter keeps managing to turn them on when she uses my truck.

bdsilverado · January 4, 2020

Well I used the diode and did the fog mod perfectly. Then tried another diode to attempt the cargo light mod but it didn't work. I haven't seen the cargo light mod on these newer trucks so I did it the same as my 17 but it just made my service engine light come on

Ravenkeeper · January 14, 2020

On 1/4/2020 at 8:24 AM, bdsilverado said:

Well I used the diode and did the fog mod perfectly. Then tried another diode to attempt the cargo light mod but it didn't work. I haven't seen the cargo light mod on these newer trucks so I did it the same as my 17 but it just made my service engine light come on

Wow. Did you have the striped end in PINK26 (brown/white)? (FYI - PINK has 27 pins to it) I've seen guys try to pin the diode into PNK27. The picture below is from my 2015 (3 diode mods), and I did my 2018 (2 diode mods) the same way. I always give the pin for the striped end first.