Turn signal switches have a busy job, especially if you do a lot of around town driving. If your Mustang still has its original turn signal switch, it has been cycled hundreds of thousands of times in a half century. We're going to replace the original turn signal switch in Carol Marini's '68 Mustang hardtop, which has been driven more than 800,000 miles in 45 years. Carol's steering column and switch are the same as found in '69s with the same replacement procedure. Though the steering wheel is different in appearance, it comes apart the same way. Turn signal switches stop working due to corroded and dirty contacts. They stop canceling when plastic detents get brittle and break off. Switch replacement is simple and takes approximately one hour.