GM Sport Bar Mounted Lights Problem

MidnightEdition · July 19, 2017

Hey guys,

So I have the sport bar with the red silverado in it. It has a place on top for a GM supplied light kit that runs you $1200 plus tax here in Canada. I tried to avoid buying their kit because it's wayyyy over priced and only gives you 6 inch bars. So I put two 12 inch bars up there and they plugged directly into the harness that is inside the sport bar. Problem is no way to turn on the lights. Called the local GM dealer and they said I needed a new headlight switch that has two buttons, one for fog lights and one for the light bars. Bought and installed that, still nothing. Brought the truck in to figure out the issue. They tell me I need a new wire harness that goes from this new switch to the BCM and a couple other places. PROBLEM: cannot buy the harness seperate from that $1200 kit. Does anyone know if I can source the harness from somewhere else or make something up?? Part # for the kit is 23415421. Thanks for any help you may be able to provide.

Silver16 · July 19, 2017

Mr. Gamboa this job should accept it will again tax your knowledge, skill sets and tenacity about GM wiring....this message will never self destruct.

BradsZed · September 7, 2017

Hey midnight, you get anywhere with this issue? Happen to have a pic of the two 12" bars?

Crazyjoker77 · September 7, 2017

I too have the sport bar and am going to add my own dual 12" light bars. The lights just arrived today and I plan on using the factory Upfitter switch(GM 23145158 for the switch panel. and GM Part Number: 13575783 for the wires to connect the relays to the switches) to control them via some standard automotive 30A relays.

I'm gonna wire it up so Aux1 will turn on my bumper LED bar. Aux 2 Will be both roof lights. Aux 3 will make all 3 led bars come on with the high beams. Aux4 is just gonna be a spare at this point but Im still gonna wire it up to a relay so I don't have to take the dash out again.

Edited September 7, 2017 by Crazyjoker77

Spurshot · September 8, 2017

... ... new headlight switch that has two buttons, one for fog lights and one for the light bars. ...

Got a part number and picture?

Crazyjoker77 · September 8, 2017

Well started my install today. Lights mounted perfectly to the stock mount with no modification.

Next up is to fish a couple runs of #12 wire down the inside of the tubes and under the cab to my relays by the fuse box. Gonna salvage the weatherproof connectors off the harness the lights came with and solder them to the newly fished wires and everything should be done.

GMMediumDutyMQ · September 11, 2017

Ultimately, you're likely going to find you don't want to pursue the stock method, anyway. If you use the OEM kit switch and harness, you're controlling everything via the BCM, which means it'll only allow you to turn on the light under very specific conditions -- if memory serves, only if your brights are on.

Wiring them up like a conventional aftermarket fog lamp kit -- even if you use the OEM aux switches -- would give you more flexibility in controlling how/ when you power these lights up.

Crazyjoker77 · September 11, 2017

Well I Did the full install of my lights onto my Lightbar and got them working.Still waiting on the factory upfitter switch so I just used a cheap 3$ toggle for now. Was a lot more work than I first thought fishing the wires through the tubes and box. Had to completely unbolt the sport bar and prop it up as the tubes don't go straight down into a pocket. I'm sure glad I ended up going with a single 10G wire to both fixtures instead of running 2#12s as it was very tight in that offset part of the sport bar. Getting the wires to come from the pocket to under the truck proved difficult as well and tested my contortionist abilities... All said and done I'm happy, lights are bright and cost me no where near the 1500+ the dealer wanted. I'll provide some pics when I get home from work.

Ultimately, you're likely going to find you don't want to pursue the stock method, anyway. If you use the OEM kit switch and harness, you're controlling everything via the BCM, which means it'll only allow you to turn on the light under very specific conditions -- if memory serves, only if your brights are on.

Wiring them up like a conventional aftermarket fog lamp kit -- even if you use the OEM aux switches -- would give you more flexibility in controlling how/ when you power these lights up.

I know how to wire the upfitter switch but I'm not quite sure exactly how it operates. The switches switch the ground from a relay coil to pull the relay in.

I'm unsure though and hope you know if:

1. can the switches be used with the truck off? or does the key have to be in the ACC position. (hot side of the coil is wired directly to batter and not Retained power)

2. If the lights are on and I shut the truck off (assuming they turn off with the truck) will they be on when the truck is started again? or do they always reset to off?

3. If there is nothing hooked up to the switch and you push it does it still light up?

silveradosid · September 12, 2017

yes the switches still operate with the truck off if you se a rap wire for the positive side of the relay then the lights will shut off the gm aux switches are like any on off switch if you use rap wire on the positive of the coil then the lights will come back on with the key

GRRW00F · November 4, 2019

On 9/7/2017 at 5:39 PM, Crazyjoker77 said:

I too have the sport bar and am going to add my own dual 12" light bars. The lights just arrived today and I plan on using the factory Upfitter switch(GM 23145158 for the switch panel. and GM Part Number: 13575783 for the wires to connect the relays to the switches) to control them via some standard automotive 30A relays.

I'm gonna wire it up so Aux1 will turn on my bumper LED bar. Aux 2 Will be both roof lights. Aux 3 will make all 3 led bars come on with the high beams. Aux4 is just gonna be a spare at this point but Im still gonna wire it up to a relay so I don't have to take the dash out again.

Hey Joker,

Do you have pics of how u wired up the lights to the upfitter switches? I just bought the switches and am confused how to run the wiring. Do you have to run the light wires to the fuse box then back to the switch or ? Any help would be much appreciated!!

rbrjr1 · November 5, 2019

On 11/4/2019 at 4:04 PM, GRRW00F said:

Hey Joker,

Do you have pics of how u wired up the lights to the upfitter switches? I just bought the switches and am confused how to run the wiring. Do you have to run the light wires to the fuse box then back to the switch or ? Any help would be much appreciated!!

there is an upfitter plug that attaches to the X61A junction block that will yield 4 wires to connect your relay switch leads to.

GRRW00F · November 5, 2019

17 minutes ago, rbrjr1 said:

there is an upfitter plug that attaches to the X61A junction block that will yield 4 wires to connect your relay switch leads to.

So I did a google search and came up with 2014-2019 CHEVY GMC JUNCTION BLOCK CONNECTOR TRUCK WITH AUX SWITCHES 15547108; would this be the correct cable you are referencing?

Edited November 5, 2019 by GRRW00F
Change info

rbrjr1 · November 5, 2019

28 minutes ago, GRRW00F said:

So I did a google search and came up with 2014-2019 CHEVY GMC JUNCTION BLOCK CONNECTOR TRUCK WITH AUX SWITCHES 15547108; would this be the correct cable you are referencing?

the actual piece I was talking about is GM 19328970. It looks like the piece you are talking about includes both switched and unswitched positive leads and lands every active pin on the X7 pinout (see upfitter bulliten here).

19328970 (at about half the price) is just the plug itself, so you could land solid runs of wire, instead of splicing into the 15547108 harness that you referenced.

GRRW00F · November 5, 2019

12 minutes ago, rbrjr1 said:

the actual piece I was talking about is GM 19328970. It looks like the piece you are talking about includes both switched and unswitched positive leads and lands every active pin on the X7 pinout (see upfitter bulliten here).

19328970 (at about half the price) is just the plug itself, so you could land solid runs of wire, instead of splicing into the 15547108 harness that you referenced.

Ok, that works perfect for the power end of things, what about the cable that plugs into the back for the aux switches or is it already there in the dash? I really appreciate the help!

rbrjr1 · November 5, 2019

28 minutes ago, GRRW00F said:

Ok, that works perfect for the power end of things, what about the cable that plugs into the back for the aux switches or is it already there in the dash? I really appreciate the help!

make sure you read through the entire AUX SWITCH thread... there are about 30 differeng Upfitter switches, and depending on what switches came with your setup, you may or may not have everything you need in the dash already.

my 2018 LT Z71 already had the upfitter provision installed on it (all the back harnesses, ready for the switch).

my vehicle came with 3 switches existing (Hill Decent/Cargo Lamps/Traction Control) and my harness that plugged into it already had the leads for the outfitter switch AUX1-4.

it might be more pertinent if you post in that thread about your questions, you're really asking about the Upfitter switch and not the light bar as is the main topic of this thread.

Edited November 5, 2019 by rbrjr1