AUX switch install

[TinkeringFox]

On 4/27/2018 at 8:00 AM, Csjumper2003 said:

Tc/cargo/and downhill assist


Sent from my iPhone using Tapatalk

Ok perfect, I just messed with one of those yesterday. The main plug that plugs into the back of it (18 cavities) is known as the (X1 connector) the smaller plug for exhaust brake or CNG (6 cavities)  is known as the X2 connector. You likely have an unused blank slot (no pins) where the CNG or Exhaust Brake would otherwise plug in with a 6 wire harness docked there (doing nothing). As far as the AUX switches 1-4 go, their output comes through pins 10-14 in the X1 connector. Your T/C and Cargo come through cavities #17&18 of this same connector. Cavities 10-14 will likely (unless you’re really lucky) have no wires present. This is where you need to insert four wires. (One for each Aux switch). You will have to disassemble the X1 connector and release the TPA lock to insert these wires but it’s not very hard. Those four wires will have a constant negative or ground signal depending on if the switch has been pressed or not. Take that signal and apply it to pin #86 of a relay as a trigger. With pin #85 connected to a switched ignition source the relay will turn on or close or switchover whenever you apply ground (negative) to pin #86 by pressing an Aux switch button. This will cause pin #30 of the relay to connect to pin #87 and out to your accessory. Pin #30 will be your  fused power supply. 

Now for the HDC button. The new CNG button is a momentary button meaning it only sends a signal as long as you’re pushing it. The HDC on your original switch works the same way but they don’t use the same output pin. You need to connect the wire from pin#4 in the X1 connector (HDC switch signal) to pin #4 of the X2 connector (CNG or Exhaust Brake control signal). These two connectors use a different terminal on the end of the wire so it’s not as easy as removing form X1 and adding to X2. If you have that 6 position or cavity plug sitting there in the blank X2 slot you can use this. The easy way would be to cut the wire coming out of pin#4 in the X2 connector with enough length to connect it to the wire coming from the X1 connector. Now your CNG switch’s output will be sending a signal through the wire from X1 for HDC. Don’t worry about removing the HDC wire from the X1 connector as it doesn’t connect to anything in the circuit board on your new switch. If you don’t have the 6 position plug X2 sitting there then you will need to buy a terminal and make a lead. I don’t recall the part number for the X2 terminal off hand but I’ll find it next time I’m at the bench.

I hope this helps and sorry for the long winded response but I just wanted to be clear.

Edited August 1, 2018 by TinkeringFox
Wrong pin # ground/power

[ChristopherDB]

I have hill descent, cargo light, and traction control buttons. I can't figure out the part# for the same buttons plus the AUX. I see the long list of parts numbers and searched Google but the images are not accurate. Anybody know? 

[TinkeringFox]

11 minutes ago, ChristopherDB said:

I have hill descent, cargo light, and traction control buttons. I can't figure out the part# for the same buttons plus the AUX. I see the long list of parts numbers and searched Google but the images are not accurate. Anybody know? 

These are the only AUX switchbanks I’ve found...

[TinkeringFox]

I’m not sure if that combination is an option but you can get it to work using 23145163 or 23146445. You’ll just to do a little wiring.

[ChristopherDB]

I wonder if I could buy 23145163 or 23146445 and then another switch bank that had the hill descent and just swap the buttons?

[TinkeringFox]

4 minutes ago, ChristopherDB said:

I wonder if I could buy 23145163 or 23146445 and then another switch bank that had the hill descent and just swap the buttons?

Um, yep....that’s exactly what was just done on page 13.

[Csjumper2003]

Ok perfect, I just messed with one of those yesterday. The main plug that plugs into the back of it (18 cavities) is known as the (X1 connector) the smaller plug for exhaust brake or CNG (6 cavities)  is known as the X2 connector. You likely have an unused blank slot (no pins) where the CNG or Exhaust Brake would otherwise plug in with a 6 wire harness docked there (doing nothing). As far as the AUX switches 1-4 go, their output comes through pins 10-14 in the X1 connector. Your T/C and Cargo come through cavities #17&18 of this same connector. Cavities 10-14 will likely (unless you’re really lucky) have no wires present. This is where you need to insert four wires. (One for each Aux switch). You will have to disassemble the X1 connector and release the TPA lock to insert these wires but it’s not very hard. Those four wires will have a constant negative or ground signal depending on if the switch has been pressed or not. Take that signal and apply it to pin #86 of a relay as a trigger. With pin #85 connected to a switched ignition source the relay will turn on or close or switchover whenever you apply power to pin #85 by pressing an Aux switch button. This will cause pin #30 of the relay to connect to pin #87 and out to your accessory. Pin #30 will be your  fused power supply. 
Now for the HDC button. The new CNG button is a momentary button meaning it only sends a signal as long as you’re pushing it. The HDC on your original switch works the same way but they don’t use the same output pin. You need to connect the wire from pin#4 in the X1 connector (HDC switch signal) to pin #4 of the X2 connector (CNG or Exhaust Brake control signal). These two connectors use a different terminal on the end of the wire so it’s not as easy as removing form X1 and adding to X2. If you have that 6 position or cavity plug sitting there in the blank X2 slot you can use this. The easy way would be to cut the wire coming out of pin#4 in the X2 connector with enough length to connect it to the wire coming from the X1 connector. Now your CNG switch’s output will be sending a signal through the wire from X1 for HDC. Don’t worry about removing the HDC wire from the X1 connector as it doesn’t connect to anything in the circuit board on your new switch. If you don’t have the 6 position plug X2 sitting there then you will need to buy a terminal and make a lead. I don’t recall the part number for the X2 terminal off hand but I’ll find it next time I’m at the bench.
I hope this helps and sorry for the long winded response but I just wanted to be clear.

So in theory I should be able to wire my train horn button to the momentary change. I hate the downhill assist anyways so that could give me an option and hide the fact it’s a train horn button


Sent from my iPhone using Tapatalk

[Csjumper2003]

Can we book mark pages in Tapatalk? Does anyone know?


Sent from my iPhone using Tapatalk

[TinkeringFox]

Yes, the momentary would work for that. You could also open one of the Auxiliary switches and remove the little “j” shaped spring and make it a momentary switch. I’ll take a picture of that next time I get to the work bench. It’s pretty easy though.

[Csjumper2003]

Yes, the momentary would work for that. You could also open one of the Auxiliary switches and remove the little “j” shaped spring and make it a momentary switch. I’ll take a picture of that next time I get to the work bench. It’s pretty easy though.

Ok so they switch on negative. So the way a relay would normally be ran for a light bar or something instead of the normal switching on a positive and positive trigger this would be negative and negative trigger.

Like the pin out info. Makes me wanna go and tear apart right now but needing to put some time aside to get it all done.

Do you know if the downhill assist is a momentary signal?



Sent from my iPhone using Tapatalk

[TinkeringFox]

Yes, all of the signals are negative. If you install the upfitter switch with the CNG or Exhaust Brake you’ll forget about the HDC and just grab that power from X2 cavity 4. 

[pgamboa]

Yes, all of the signals are negative. If you install the upfitter switch with the CNG or Exhaust Brake you’ll forget about the HDC and just grab that power from X2 cavity 4. 

ABSOLUTELY LOVE the diagrams and your explanations!


Sent from my iPhone using Tapatalk

[Csjumper2003]

Yes, all of the signals are negative. If you install the upfitter switch with the CNG or Exhaust Brake you’ll forget about the HDC and just grab that power from X2 cavity 4. 

Ok a little confused with HDC and Upfitter switch.

Is hdc the fuse panel that oem would have relays if your truck was oem equipped with the aux six switches?

I bought the oem gm switch off eBay. Well at least it says it is oem and is gm logo on it. So I’m missing a connect. The plug you pictured is the one the 3 switch is connected 2 and another one doing nothing behind? And then I was a little confused when you mentioned if you have upfitter switch. Is this meaning If you have the oem relays and all run?



Sent from my iPhone using Tapatalk

[TinkeringFox]

Here is the back of your new “Upfitter Switch” from eBay.

 The smaller socket (X2) is where the Exhaust Brake or CNG plug if you had that would plug into. Although you never had either of those options you may very well have the harness sitting there plugged into a blank socket in the X2 position. You can plug this harness into the new “Upfitter Switch” from eBay and use the wire that goes to pin number four in that X2 connector. PIN number four in the X2 connector is the one coming from the CNG button and it is a momentary negative signal. This can be used to trigger a relay for your air horn since it only sends a signal while you’re pressing the button. 

 

The other switches send send their signal through the larger X1 connector (18 position). Pins 17&18 are your traction control signal and your cargo lamp signal. (Both are momentary negative signals) These signals go to the BCM and tell it to do what it does. Your ”Upfitter”  or “Aux” switches use pins 10 through 13 (10,11,12 &13). These switches send their constant negative signals through these pins. Your harness that is plugged into X1 will likely not have any wires occupying pins 10-13. You will have to add these wires (13575782) https://www.gmpartsdirect.com/oem-parts/gm-f--s-wire-13575782

these wires can be used to trigger 4 different relays in your under hood fuse box X50A or 4 relays from BFE Amazon or eBay wherever. They send a negative signal until you press the button again.

 

[Csjumper2003]

Here is the back of your new “Upfitter Switch” from eBay.

 The smaller socket (X2) is where the Exhaust Brake or CNG plug if you had that would plug into. Although you never had either of those options you may very well have the harness sitting there plugged into a blank socket in the X2 position. You can plug this harness into the new “Upfitter Switch” from eBay and use the wire that goes to pin number four in that X2 connector. PIN number four in the X2 connector is the one coming from the CNG button and it is a momentary negative signal. This can be used to trigger a relay for your air horn since it only sends a signal while you’re pressing the button. 

 

The other switches send send their signal through the larger X1 connector (18 position). Pins 17&18 are your traction control signal and your cargo lamp signal. (Both are momentary negative signals) These signals go to the BCM and tell it to do what it does. Your ”Upfitter”  or “Aux” switches use pins 10 through 13 (10,11,12 &13). These switches send their constant negative signals through these pins. Your harness that is plugged into X1 will likely not have any wires occupying pins 10-13. You will have to add these wires (13575782) https://www.gmpartsdirect.com/oem-parts/gm-f--s-wire-13575782

these wires can be used to trigger 4 different relays in your under hood fuse box X50A or 4 relays from BFE Amazon or eBay wherever. They send a negative signal until you press the button again.

 

 

 

Ok last questions I think.

What is HDC?

 

So does the pins for tc and cargo, need to be moved in the plug?

 

Also you mentioned there is the 2nd plug behind for the smaller one. Do you cut the factory wires in order to run them to your own relays? Or in that oem plug there is nothing actually usable that is already there and you have just plug in some pig tails?

 

Lastly the link you sent are these the pigtail wires with connector to pop in? I couldn’t find a pic on any gm website

 

 

Sent from my iPhone using Tapatalk