I don't use mechanical t/s at all anymore since my brain has decayed and I leave them on or they fail to cancel. I use the motorcycle all electric set up which blinks 7 times with a quick push, 11 times with a 1 second push, and 22 times with a 2 second push. Push both buttons and you have 4 way flashers till you cancel them. The momentary push buttons can be anywhere; mine are out of sight on the bottom lip of the dash. Only worked trouble free for 30 years so I can't give a definitive statement on their life span.