A word of advice...  Don't waste your time and money with the factory switch on the turn signal lever.  It's expensive to buy/replace (dealer only item - if I remember correctly) and it is common for them too wear out often, frequently, prematurely, etc.  Very poor design!  
Just get a toggle switch and keep it simple!  I re-wired my factory fog lamps and bought a rocker switch.  I then mounted it in one of the blanks underneath the heater controls.  Works great!