AUX switch install

[C_Hag183]

Just realized that came off kinda douchey

not intended at all 

 

Cheers!

[SwitchBladeSierra]

Hello, wondering if anyone can help me with this little problem. I was trying to order the Upfitter Switch that has TC, Cargo Light, Blank, Aux 1-4.... Order was cancelled due to "not having it". The only available option to me now is the Upfitter Switch that has all these options, but in the blank space there is "Exhaust Braking". My truck is a gasser, so this is of no use to me.

 

I need to find where Pin 4 and Pin 5 of the X2 connector run to (i.e X61A - X1 - Pins X & Y), and manipulate that somehow to get my desired outcome. Has anyone done this? Would there be any implications with me just doing nothing with it and installing it as is and never using it? I have gathered that it is "momentary" - so there are some considerations there.

 

Please help!

Edited Wednesday at 10:32 PM by SwitchBladeSierra

[SwitchBladeSierra]

On 8/12/2026 at 6:09 PM, SwitchBladeSierra said:

Hello, wondering if anyone can help me with this little problem. I was trying to order the Upfitter Switch that has TC, Cargo Light, Blank, Aux 1-4.... Order was cancelled due to "not having it". The only available option to me now is the Upfitter Switch that has all these options, but in the blank space there is "Exhaust Braking". My truck is a gasser, so this is of no use to me.

 

I need to find where Pin 4 and Pin 5 of the X2 connector run to (i.e X61A - X1 - Pins X & Y), and manipulate that somehow to get my desired outcome. Has anyone done this? Would there be any implications with me just doing nothing with it and installing it as is and never using it? I have gathered that it is "momentary" - so there are some considerations there.

 

Please help!

For anyone following, this is what I have deduced from this forum - and my very specific niche case. Please do let me know if you see me going in the wrong direction here. For context, I have a 16 sierra 1500 w/t. Has TC and Cargo light switches. Removed the switch to find the X1 and X2 of the S48A connection populated with wires (x1 10-14, and x2 1-5).

 

Took photos of the X61A-X5 to find the wires from S48A-X1 land here at their respective pins (10, 11, 17, 23 on the X5). Was hopeful that this means my X51A fuse box has the appropriate pins... No cigar. So now I will be routing wires from the rear of the X61A-X1 to the engine bay and to their respective negative relay triggers. Please see to the diagram. If any has insight as to where the S48A-X2 pins 4 and 5 land that would be awesome.

 

Will be attempting this sometime shortly and will likely make a youtube video out of it.

 

Note: please disregard fuse sizes. Main fuse will likely be 25A, all mini bus fuses will likely be 10-15A.

 

Here is my parts list:

• GM 84347199 - TC, Cargo Light, Exhaust Brake (useless to me unless I find a means to reconfigure), Aux 1 - 4.
• 12V 6 Way Pre-Wired Fuse Relay Box Kit with 4 x 40A 4-Pin Relays (link below - some mods required to make negative trigger)

           https://www.amazon.ca/dp/B0F4KCS43B?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

• Various wire sizes (12 AWG - red and black, 14 AWG, 16 AWG multi-colored bundle)
• Wire termination leads for X61A-X1 (unknown at this time)
• Crimp connectors/Soldering Gun
• Heat Shrink
• Split Wire Loom

To be continued... 

 

Cheers

Edited 25 minutes ago by SwitchBladeSierra