I have a 2015 SGS, just added switch kit 71400105. It came with (2) accessory switches(middle and right) left switch was a blank. I added a fog lamp switch (71400044) to take place of the blank. I also purchased the wiring harness supposedly needed for under left side cover. The problem I'm having is locating what terminal the new fog lamp switch activates. Found numbers 2 and 3 when I plugged in wiring harness. Can't find any unused terminals that are switched by number 1. Any advise?

 

Number 1 (furthest left) is for Aux lights and controlled automatically by the BCM, the aux lights are connected at the turn signals.

Number 2 is also automatically controlled by the BCM, I used mine for Fogs, and there are several ways to route them, I used accessory harness which plugs into accessory plug under left side cover and it offers a sort of 3 way for further accessories (high amp, low amp [or something like that] and an extra accessory plug so you don't lose it on account of the Fogs taking up the spot.)
Number 3 I haven't messed with yet.

Right side number 1 and 2 are saddlebag locks/momentary switches (gonna use it for a garage door opener, that's my plan) it's a CVO dash panel switch pack, and not in HDs catalogs, which is why they will tell you it's not available.. but you can get it on Boardtracker or another sales point.

Generally I've found you can pretty much plug in anything (within reason) the BCM will know what to do.

 

What was mentioned as well is the extreme left switch is wired back to the BCM which controls the AUX light wiring located in the same connector as your turn signals. Its a four pin connector located under the turn signal bracket, both right and left side. The other wires are all hot wires leading to the Aux Connector under your Left Side cover. There are fused off of your P&A fuse and are low amp wiring. If your going to use for high amp they can be used to operate a Relay wired to the battery with proper fuse sizing.
Here is a write up I did some years ago explaining it all in detail. Hope this helps.
https://www.hdforums.com/forum/touri...l#post12280183

 

Just wanted to say thanks again to Onedef and Glidin Joe. Found the power right where you said it was

 

Big thank you to the OP and others who provided info in this thread. This weekend I was able to cobble together my own custom aux setup. Like the HD <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->69200722 kit, I added a deutsch 4-position and then built my custom harness with GPS, USB, etc wired into a female receptacle and it's all slick as can be. Very clean!