Dennis, as Jerry suggested you can use a 12 volt battery on your old Sears Timing Light. The battery from another car, your riding mower battery any 12 volt will do. It doesn't have to be in your truck just set it on a fender cover and hook up the pos/neg leads of the timing light and hook the pick-up as Jerry said to 1 or 6 and fire her up. Light should be as bright as new. Good luck.
