This problem has being ongoing for a while now and its being a massive pain, Currently i've already replaced the alternator, glow plug relay and the battery. The interior lights and dash backlight flash very bright every now and again as well as the volts bouncing up on the dash every time it happens, if i have my radio on it also makes a clicking noise. Even the windshield wipers have gone off by theirselves when the click happens and im clueless to what has caused it, when checking the volts on everything ive noticed the voltage to the glow plugs never leaves even after the light has turned off for it. At first i thought it was the alternator overcharging but even after replacing it with a new one nothing has fixed it