I would like to use the momentary contact toggle for the (alas, never to be activated) rear fogs to control a Sprint Booster. Does anyone know where I can easily pick (tap) up the wires to the switch? Thanks.

 

None of the toggle switches are connected to wires. Flipping a switch causes a message to be sent on the digital bus to the footwell module.

 

Understood, but wires run from switch module to footwell module. Hoping to find that run and explore intercept. There will be either a pair of wires or one wire, if the other pole goes to common ground, for each toggle. Do you know where that harness runs? Trying to avoid dash disassembly as the use is not with that effort. Thanks.

 

That's not how it works. None of the toggle switches has a direct wire connection. The toggles are on a circuit board. The circuit board detects a switch being pressed and converts it to a message for the CAN bus. What comes out of the switch panel is a connection to the CAN bus, not wires for each switch. If you want to intercept a switch press, you'd have to hack the circuit board, or have a device that reads signals on the CAN bus.

btw, these can't even be called "toggle switches" in the traditional sense. They are plastic levers that press on capacitive pads on a circuit board. Here are pictures of the inside of the switch panel on R53. It would be a similar design for an R56: https://margaretandian.com/2005/04/2..._switch_panel/

 

what has been done by some is to open up the switch bank as shown

and drill holes ... then insert a similar looking switch and run 'plain' wires out the back and go from there .....

I'm not recommending ... just sayin' it has been done .....

if you mess up the card that the other switches run off, you have a problem on your hands ....

 

Now I get it, I assumed the switches were just that, not part of an integrated circuit that send the digitized message to can bus. Thanks to all for answers.