I was driving my 2005 Focus ZX3 two days ago and the headlights started switching between low and high speed very rapidly like a police car. The next day while driving all the instrument panel gauges started going haywire, the vehicle wanted to stall but I kept my foot on the pedal and made it to an Autozone. They checked the battery and alternator and said they were good. I had replaced the battery a year ago and installed an Autozone alternator only a month ago. The vehicle wasn't safe to drive and I had it towed to a Ford dealership. The technician said it ran smoothly and couldn't find any problems. Any advice from the experts what could be causing this intermittent electrical problem?