I un-soldered the wires in the FTP switch and used the it as a momentary-on switch to trigger a garage door opener. That bike is gone but in trying something similar on my Gold Wing I came up with an improvement for the C-14. As I did it, you can solder a pair of wires to the circuit board of a door opener remote and use the FTP sw. to activate. But, this means anyone could activate it without the key being on.
 
Another way is to use the switched FTP wires to activate an automotive Relay ($5), and have the relay activated circuit trigger the Garage door remote.  This way you retain the FTP function and gain the security of having the garage door activated by a circuit that only works when the key is ON.

The C-14 switch is perfectly situated so you can open the Garage door without taking your hands off the bars.

Would you have pictures or a diagram for us electronically challenged?

Would you have pictures or a diagram for us electronically challenged?

of for us electronically useless? 

Sorry, mine is buried and I didn't take pictures.

I used a typical 3 button remote. Take it out of its housing and you have a circuit board/battery with 3 micro switches that typically have 4 connections each soldered to the circuit board. You can use any of the buttons. With the remote battery in place, use a short piece of wire, momentarily touch connections on opposite sides of the button  until you find two that, when connected momentarily, activate the garage door. The idea is to solder a wire to each of those two connectors and when the other two ends are connected will activate the door opener.

I found a relay at the auto shop for $4.99. It's a cube about 1" on a side. It has 5 prongs on the back. There's a simple diagram on the package. The concept is, when 12 volts are applied through 2 prongs, an electro-magnet inside makes a connection between 2 of the other prongs, only as long as voltage is applied then it breaks the connection.  (Ignore the 5th prong)

The flash-to-pass switch momentarily switches a 12 volt current when pressed, then stops when released. if you pass that 12v through the relay, it completes a circuit between two OTHER prongs of the relay. If you use those 2 switched prongs to make a circuit for the wires to the remote it will complete the circuit only when the FTP trigger is depressed. AND, that voltage is only present when the key is on. (I believe, I can't verify that, I don't have a bike)

On my bike, I un-soldered the wires from the FTP switch and used it as a momentary on to trigger my door opener. Using the relay allows the FTP to function normally, as well as trigger the door opener.  AND it's non-functional when the key is off.

I'm a total idiot when it comes to electricity but this is pretty simple. Use caution when soldering wires to the remote circuit board, too much, in the wrong place will ruin the remote. I routed the wires as discretely as possible and placed the remote where it is hidden & protected. The location varies but the glove box works well.
This photo might help.. I made a hole in the remote case for the wires so it can be buttoned up normally.
I believe the two horizontal prongs (IE: Left and Right in the photo) are for the "signal" 12v. and 2 of the vertical prongs are the "switched" pair to complete a circuit..

This will only work with the Gen 1 bikes correct? Gen 2 uses that switch to toggle through the dash displays.

This is a great idea though. 

Actually multiple functions as Phil described can be done by any switch and relay combination. I would have to look at the schematic for both models to wring out the wiring but it is very straightforward as long as both wires from the switch are available. And even if they are not, the switch can easily be opened and new wires attached to it.

Brian

This will only work with the Gen 1 bikes correct? Gen 2 uses that switch to toggle through the dash displays.

This is a great idea though. 

Yes, I had a GEN-1 bike so this may not apply to later versions. Any momentary on 12v source can be the switching circuit. If you chose to add a momentary-on push button switch, pick a wire that is hot when the key is on to do the relay switching, then your garage opener will function only when the ignition is on.

This will only work with the Gen 1 bikes correct? Gen 2 uses that switch to toggle through the dash displays.

This is a great idea though. 

On Gen 2's the Flash-To-Pass function is part of the headlight Hi/Lo switch and the switch used to toggle through the display is a totlay different switch. 

love my flash to pass, lighting up curves at night, signal passing, signal move please!! lol

not worth removing compared to carrying a small remote opener.

You don't have to sacrifice the FTP function! Just add another feature, and you don't have to remove your hands from the bars. I have a curving driveway heavily populated by squirrels, and sometimes need to avoid them, so that's important to me.

As Phil already said, you can have both or even more functions out of that one switch if you use a relay(s). The FTP function will work as it always has and you can add a garage door opener, a burglar alarm shut off, etc., etc. as needed and wanted.

Brian

love my flash to pass, lighting up curves at night, signal passing, signal move please!! lol

not worth removing compared to carrying a small remote opener.

I use a very similar-in-theory after-market device, ironically called "flash-2-pass", which is activated by a double click of the bike's headlight hi beam switch, and sends a signal to a receiver wired into garage door's electric motor switch. Works great. I have them on both of my current bikes, and have used them on several bikes in the past. No doubt more expensive than OP's solution, but can be used, with additional receivers, on more than one garage door. If a person has different garages, maybe at different locations, this solution works well. More expensive, though. Can reportedly also be activated with a smart phone, though I have yet to figure out why you would want to do that.

You can solder wires to the standard garage door opener and splice them to a water proof momentary button or reset button also.

Just stash the opener in your fairing someplace.