Using just a six-in-one screw driver I followed the videos to replace the timer and thermal sensor, the top two most common issues for my described issue. I took pictures of wiring using my cellphone, but didn’t need the pics as I removed wires from old timer and immediately attached to new timer, removing any issue with confusing wires or terminals. With three tests completed, it seems to be working again. Hopefully it will work for another 15 years..