Retrofit ‘25 Overtrail Aux Switches

[TenaciV]

Hey folks, starting a thread to detail plans on retrofitting my ‘24 OT with the ‘25 OT aux switch buttons. I am not looking to recreate the full OEM electrical harness, rather only the OEM look and finish of the ‘25 OT buttons. Any constructive feedback or alternative suggestions are more than welcome!

Why? I want physical switches to complement my existing Garmin Powerswitch in case my phone dies to have as a backup.

Approach

• Tie the Aux switches into the existing “Control Input” function of the Garmin Powerswitch
  • The Powerswitch only has 2 slots for Control Inputs so technically I only have space for 2 functioning switches - this isn’t a limiting factor for me at the moment
  • Those 2 slots are fed by “trigger” signal wires (which I assume will come from the Aux switches upstream) - requires 3.3-18v input to activate
• Looking at the Caliraised switch wiring diagram - there are 5 connections that need to be sorted for a single button
• 
  • 1 (Yellow) - Fed by either the 5A “Panel” fuse (which I think is the glovebox fuse panel that 2 down and 2 to the right starting form the top left but I am not sure, pasting Glove box fuse panel below for reference OR see if this happens to work for our GX550’s
  • 2 (Red) - Fed by “ECU ACC” fuse from the same glovebox fuse panel - I am only trying to take a voltage signal from this circuit to pass along to the Garmin Switchbox once the respective Aux button is in the “On” state
  • 3 (White) - Assume this is common ground that I can find near the glove box panel?
  • 4 (Green) - Signal wire that will run to Control Input of Garmin Power Switch
  • 5 (Black) Ditto for 3/White?
• 
• Routing electrical through the firewall - I plan on emulating this post’s approach

Parts List (so far):

• ‘25 OT Lower Panel that has the Aux Switch holes, #: 55432-60800-C0
  • TBD on arrival date - will keep folks apprised on ETA
• Switches/Buttons - 2 options OEM or Caliraised, I’m inclined to go w/ Caliraised for now as the OEM switches are like ~$80 USD a piece
  • OEM 1-4: 84484-AK040, 84484-35030, 84485-AK010, 84485-AK020
  • Caliraised
• Wires/Wiring
  • Dash Aux Buttons <-> Glove Box Panel (wiring for 2 functional buttons)
    • 5 Conductor 18 AWG
      • C1 - Shared for both buttons - backlight
      • C2 - Shared for both buttons - Signal feed that is only passed along once the button is pushed - only want this on when the car is in ACC or On
      • C3 - Common ground that should be able to be combined with White/Black from the Switches
      • *C4 - Button Aux 1 Signal (Green for Switch 1) - can’t be shared as this will feed C1 on the Powerswitch
      • *C5 - Button Aux 2 Signal (Green for Switch 2) - can’t be shared as this will feed C2 on the Powerswitch
    • *C4 & C5 will be spliced at the Glovebox fuse panel to a 2 Conductor wire
  • Dash Aux Buttons <- Firewall -> Garmin Powerswitch
    • 2 conductor 18 AWG
      • C1 - Splice into C4 from 5 conductor wire above
      • C2 - Splice into C5 from 5 conductor wire above
    • I may increase this to a 5 or 6 conductor wire for future use & button expansion - cap and seal the unused wires for the time being

Questions/Unknowns:

• I don’t think a relay is required in this setup as there are no high loads - this is all either small leds loads or signal wire feeds - the Powerswitch is handling the heavy loads
• There are 4 slots for Aux buttons in the ‘25 OT trim panel - I only plan on using 2 of those slots for actual buttons - I need to find 2 blanks for the unused slots. Does anyone know the part number for those square blanks?

Other Comments:

• Found the Fuse Panel to system list for the engine compartment panels - I will be printing these out and keeping them with my spare fuses for future reference. I know that when I need this list, cell phone service will invariably fail me to pull it up.
• Page 500 of the owners manual shows how to access the Glovebox fuse panel

I think that’s it for now…any additional suggestions on the approach is more than welcome!

 

[Garauld]

The attached schematic may be of use to you. Happy wiring!

 

[TenaciV]

The attached schematic may be of use to you. Happy wiring!

Thanks for sending that, much appreciated! By chance, do you have anything similar for wiring/connectors of the other buttons in that vicinity? Would be great to know if I could piggyback on of those connectors from A, B,C,D,E,F or H.

 

[Garauld]

Possibly. Send me a PM to take offline.

 

[haze0126]

Hey folks, starting a thread to detail plans on retrofitting my ‘24 OT with the ‘25 OT aux switch buttons. I am not looking to recreate the full OEM electrical harness, rather only the OEM look and finish of the ‘25 OT buttons. Any constructive feedback or alternative suggestions are more than welcome!

Why? I want physical switches to complement my existing Garmin Powerswitch in case my phone dies to have as a backup.

Approach

• Tie the Aux switches into the existing “Control Input” function of the Garmin Powerswitch
  • The Powerswitch only has 2 slots for Control Inputs so technically I only have space for 2 functioning switches - this isn’t a limiting factor for me at the moment
  • Those 2 slots are fed by “trigger” signal wires (which I assume will come from the Aux switches upstream) - requires 3.3-18v input to activate
• Looking at the Caliraised switch wiring diagram - there are 5 connections that need to be sorted for a single button
• View attachment 12160
  • 1 (Yellow) - Fed by either the 5A “Panel” fuse (which I think is the glovebox fuse panel that 2 down and 2 to the right starting form the top left but I am not sure, pasting Glove box fuse panel below for reference OR see if this happens to work for our GX550’s
  • 2 (Red) - Fed by “ECU ACC” fuse from the same glovebox fuse panel - I am only trying to take a voltage signal from this circuit to pass along to the Garmin Switchbox once the respective Aux button is in the “On” state
  • 3 (White) - Assume this is common ground that I can find near the glove box panel?
  • 4 (Green) - Signal wire that will run to Control Input of Garmin Power Switch
  • 5 (Black) Ditto for 3/White?
• View attachment 12161
• Routing electrical through the firewall - I plan on emulating this post’s approach

Parts List (so far):

• ‘25 OT Lower Panel that has the Aux Switch holes, #: 55432-60800-C0
  • TBD on arrival date - will keep folks apprised on ETA
• Switches/Buttons - 2 options OEM or Caliraised, I’m inclined to go w/ Caliraised for now as the OEM switches are like ~$80 USD a piece
  • OEM 1-4: 84484-AK040, 84484-35030, 84485-AK010, 84485-AK020
  • Caliraised
• Wires/Wiring
  • Dash Aux Buttons <-> Glove Box Panel (wiring for 2 functional buttons)
    • 5 Conductor 18 AWG
      • C1 - Shared for both buttons - backlight
      • C2 - Shared for both buttons - Signal feed that is only passed along once the button is pushed - only want this on when the car is in ACC or On
      • C3 - Common ground that should be able to be combined with White/Black from the Switches
      • *C4 - Button Aux 1 Signal (Green for Switch 1) - can’t be shared as this will feed C1 on the Powerswitch
      • *C5 - Button Aux 2 Signal (Green for Switch 2) - can’t be shared as this will feed C2 on the Powerswitch
    • *C4 & C5 will be spliced at the Glovebox fuse panel to a 2 Conductor wire
  • Dash Aux Buttons <- Firewall -> Garmin Powerswitch
    • 2 conductor 18 AWG
      • C1 - Splice into C4 from 5 conductor wire above
      • C2 - Splice into C5 from 5 conductor wire above
    • I may increase this to a 5 or 6 conductor wire for future use & button expansion - cap and seal the unused wires for the time being

Questions/Unknowns:

• I don’t think a relay is required in this setup as there are no high loads - this is all either small leds loads or signal wire feeds - the Powerswitch is handling the heavy loads
• There are 4 slots for Aux buttons in the ‘25 OT trim panel - I only plan on using 2 of those slots for actual buttons - I need to find 2 blanks for the unused slots. Does anyone know the part number for those square blanks?

Other Comments:

• Found the Fuse Panel to system list for the engine compartment panels - I will be printing these out and keeping them with my spare fuses for future reference. I know that when I need this list, cell phone service will invariably fail me to pull it up.
• Page 500 of the owners manual shows how to access the Glovebox fuse panel

I think that’s it for now…any additional suggestions on the approach is more than welcome!

Seems like a lot of expense for the unlikely event that if your phone dies. Especially when you can turn on the lights manually at the PowerSwitch until you have power back in your phone.

 

[YellowLab]

Think through the logic - in order to turn on the lights or accessories you would need a battery or have the car running. If that is the case - does it not make sense just to simply plug in your phone into any of the USB C adaptors and you have power to your phone. If the battery on the GX is dead - there is nothing to turn on anyway even if your phone works.

If this project is to fill a wiring fettish - you can always rewire the entire vehicle on a Saturday for fun

 

[nartmot]

I think its a neat project. I already have a 2025 but I can certainly appreciate the ambition and the thorough documentation. Rock on @TenaciV ! People like you are crucial to building online communities like this.