Foglights On With High Beams

Billy 2497 · May 6, 2020

On 7/12/2014 at 3:19 PM, Spurshot said:

There's a Radio Shack on the west side of 23 by Walmart if you don't want to wait.

I know it's a 6 year old thread but couldn't help but notice that RadioShack you're talking about is the same one that closed lol, now it's an AT&T store

Ravenkeeper · May 11, 2020

On 5/6/2020 at 12:44 AM, Billy 2497 said:

I know it's a 6 year old thread but couldn't help but notice that RadioShack you're talking about is the same one that closed lol, now it's an AT&T store

A bunch of them have closed, including the one in Mojave, CA, and at the Antelope Valley Mall in Palmdale.

Billy 2497 · May 12, 2020

32 minutes ago, Ravenkeeper said:

A bunch of them have closed, including the one in Mojave, CA, and at the Antelope Valley Mall in Palmdale.

Not surprised. I just got 10 of those diode rectifiers on Ebay for $1.79 lol

George Sack · July 16, 2020

Just an FYI. On the 2019 HD2500 the two wires are brown and violet. Not striped. Thank you for the info, it worked perfectly.

George Androulakis · October 28, 2020

SO I tried this this afternoon. Thought I was doing everything right, but it just doesn't work. Lights still operate as normal.

These are the diodes i bought from amazon:

https://www.amazon.ca/gp/product/B008UFX95U/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1

I tried the 10-22 jump with the stripe facing pin 22. On my 17 Silverado, seems like the #10 wire is brown and the 22 is blue. Am I doing something wrong, or did I get the wrong diodes or what?

Help!!!!

Thanks,

George

Ravenkeeper · October 30, 2020

On 10/28/2020 at 10:48 AM, George Androulakis said:

SO I tried this this afternoon. Thought I was doing everything right, but it just doesn't work. Lights still operate as normal.

These are the diodes i bought from amazon:

https://www.amazon.ca/gp/product/B008UFX95U/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1

I tried the 10-22 jump with the stripe facing pin 22. On my 17 Silverado, seems like the #10 wire is brown and the 22 is blue. Am I doing something wrong, or did I get the wrong diodes or what?

Help!!!!

Thanks,

George

George,

Post a picture of your BCM, please. I run 1N4004 diode from hi-beam (stripe, BCM-BRN-18) to fogs (BCM-BRN-10). For yours, stripe end in 22, and other end in 10.

Edited October 30, 2020 by Ravenkeeper

George Androulakis · October 30, 2020

That's what ive been trying to do, but just using the legs of the diode, not t-taping the factory wiring. Maybe its just not going in deep enough to make the electrical connections?

See pics below.

Thanks!

George

Edited October 30, 2020 by George Androulakis

Ravenkeeper · October 31, 2020

12 hours ago, George Androulakis said:

That's what ive been trying to do, but just using the legs of the diode, not t-taping the factory wiring. Maybe its just not going in deep enough to make the electrical connections?

See pics below.

Thanks!

George

Yeah, your "non-striped end" is NOT in far enough. I used the smallest cross-tip jewelers screwdriver I have to work a path into each slot, beside the pin. Run the lead down the same corner that you made the path. Run the lead as straight as possible to get it in. Yours looks weaved through the wires.

George Androulakis · October 31, 2020

So Thanks to your help, I got it working!

What I ended up doing was getting some sold core 18ga wire I had laying around and making two pigtails, Stripped the wire about 5/8 of an inch on each side, and inserted them into the BCM connector. They went further than I thought. Then I soldered each end of the diode to the pigtail. Taped the pigtails to the wire loom going to the brown connector, wrapped the diode in tape and taped that to the outside of the harness. Best of all, it works! I now have fogs on with parking lights etc....

Thanks again for all the advice / help!

George

High Seirra 4x4 · April 24, 2021

On 10/31/2020 at 1:42 PM, George Androulakis said:

So Thanks to your help, I got it working!

What I ended up doing was getting some sold core 18ga wire I had laying around and making two pigtails, Stripped the wire about 5/8 of an inch on each side, and inserted them into the BCM connector. They went further than I thought. Then I soldered each end of the diode to the pigtail. Taped the pigtails to the wire loom going to the brown connector, wrapped the diode in tape and taped that to the outside of the harness. Best of all, it works! I now have fogs on with parking lights etc....

Thanks again for all the advice / help!

George

Will be giving the a try soon. Thanks!

High Seirra 4x4 · May 8, 2021

Took me about 10 minutes as it is a tight work space and I bent the wires on the first diode trying to get them in the plug. Tried the 2nd diode and had it working shortly. I did the #10 to #22 jump.

Thanks for all the write ups, pics and tips.

JonAllen356 · January 19, 2023

The thread's been dormant for a couple years, but why not revive it and ask a question that I haven't seen yet...

Is there a configuration that would automatically put fogs on while the low beams are active but turn them off when high beams are active? Could this be done and also preserve the ability to turn them on or off using the manual button?

I like the additional low light of the fogs, particularly how they light up the immediate road while I'm making a turn. I often turn them on manually, but would prefer to have them turn on automatically. However, I don't want them on while the high-beams are active because I drive in states where that is illegal. So the 10-18 and 10-22 mods don't work because they pair the fogs up with the highs (if I'm understanding correctly).

I did find a thread from a guy named Coby7 that said he accomplished it by "adding diodes between H4 and K2 to C2 ( Cathode at C2 of course ) of connector 4 of the underhood fuse block" but he didn't post any pictures or a diagram for where those connections are. It is found at:

I drive a 2018 GMC Sierra 1500 Texas Edition

Edited January 20, 2023 by JonAllen356

Ravenkeeper · February 8, 2023

On 1/19/2023 at 9:27 AM, JonAllen356 said:

The thread's been dormant for a couple years, but why not revive it and ask a question that I haven't seen yet...

Is there a configuration that would automatically put fogs on while the low beams are active but turn them off when high beams are active? Could this be done and also preserve the ability to turn them on or off using the manual button?

I like the additional low light of the fogs, particularly how they light up the immediate road while I'm making a turn. I often turn them on manually, but would prefer to have them turn on automatically. However, I don't want them on while the high-beams are active because I drive in states where that is illegal. So the 10-18 and 10-22 mods don't work because they pair the fogs up with the highs (if I'm understanding correctly).

I did find a thread from a guy named Coby7 that said he accomplished it by "adding diodes between H4 and K2 to C2 ( Cathode at C2 of course ) of connector 4 of the underhood fuse block" but he didn't post any pictures or a diagram for where those connections are. It is found at:

I drive a 2018 GMC Sierra 1500 Texas Edition

18-10 is Fogs with Highs (I have)

22-10 is Fogs with Running/Parking Lights

If you strictly want Fogs on with low beams, jumper the diode with non-stripe on 10 and the striped end on either 1 or 2.

JonAllen356 · February 8, 2023

7 hours ago, Ravenkeeper said:

18-10 is Fogs with Highs (I have)

22-10 is Fogs with Running/Parking Lights

If you strictly want Fogs on with low beams, jumper the diode with non-stripe on 10 and the striped end on either 1 or 2.

Great! I wasn't sure if it was going to be possible. I ordered the diodes and will give it a try next week. Should have plenty of attempts at it since the cheapest thing on Amazon was a 100 pack...

MikeBMW · February 9, 2023

I did this a few years ago without any mods.
I got the BTDiesel Autosync OBD dongle and connected it to the BTDiesel site for modding a few hundred BCM items as well as a few HMI mods.
Options are amazing (changed the rear lock out button to rolling up all windows, for one)
Anyway, this method in the thread is, certainly, a lot less expensive.

Edited February 9, 2023 by MikeBMW