[mole2]

Originally Posted by bwader

A thought I had was to hook up a diode in between the two signal wires on both sides to prevent feedback.

The way I did was tested it with wrapping wire around one turn signal lead on both sides like explained above to a diode with current flowing to the signal indicator bulb and other wire of bulb to ground. It lit up this way and could get it to blink like normal by changing the wiring.
Putting diodes in between the wires would keep current flowing just to the turn signals.

The very first day I had my bike inspected, the other car mechanic mentioned he had a friend who wired his turn signals with toggle switched.

Why don't you just order that ready made adaptor from J&P Cycles and wire it in. There is no current draw involved other than the indicator bulb. The right side wire and the left side wire get wired to the wires with the dioes and the "Y" configuration gets hooked up to one side of the socket and the ground to the other. It changes the setup from a metric setup to a US type setup is all it does. You'd be done right now and happily riding instead of working on the bike.