GR,
They are also called winkers. If you still have the original, it's a smallish rectangular metal can, maybe a half-inch bu 3/4 inch. Connected wires are BLACK and GRAY.
There are a few other things you should check first. Did you replace turn signal bulbs when it stopped working? If yes, chances are you put in the wrong ones. Are your electrical connections all clean and tight? If not, you may be loosing some voltage across bad joints thus reducing the current flow through the winker such that it won't heat up enough to flash.
You may wana replace your winker anyway. If you do, look for a 3-prong electronic replacement. You will find an unused GREEN (ground) wire floating behind the stock winker. Connect the green wire to the new flasher's GROUND or (-), the black to BATT or (+) and the gray to LOAD. An electronic flasher unit with 1/4 inch male blade connectors would slip right in!
As a side note, I'm the 2011 World Tour/Relay coordinator for Michigan and I'm looking for riders in the GR area. If you and your buddies are looking to ride with fellow SOHC4 riders, send me a PM and I'll fill you in!