Well the closest I got to setting that up without replacing the bulb in the blinker ( to a dual filament) was I rerouted the clearance light by the headlight to be the indicator (it blinked) and the original blinker just stayed on the whole time. Had that running for a few months but switched back since people had a hard time seeing my indicator.
Found a post on what you're trying to do (I think) on the org. Here's the link to the how-to:
http://csc.smsu.edu/~jack/max/blinkermod.html 