The winker circuit works like this:
The Black wire to the winker is 12 volts, the Grey one goes to the center of the L-R turn switch. It only applies the load to the winker when the switch is set to either L or R, at which point the winker starts cycling. So, if it is always cycling now, the Grey wire is somehow connected to either a load, or grounded accidentally. They wink away happily when accidentally grounded on the Grey wire, just has a real short ON time.
Maybe that will help?