Electrical issues that are difficult to diagnose—and sometimes intermittent—are typically due to ground wiring issues. The most troublesome ground locations are under the battery or at the engine.Google+
Car Problem Reports
Volkswagen Jetta TDI Difficult to Diagnose Electrical Issues Are Typically Due to Ground Issues
Volkswagen Jetta TDI Problem
Average Mileage: 187,500 mi (140,000 mi - 235,000 mi)
Visitor, 2005 Volkswagen Jetta TDI, 140,000 mi
more and more frequently, i get in the car to start it and i notice that the clock is at 1200. the trip odometer is at zero. the overall odometer reads the mileage. turning the key will make( on occasion) a ticking sound. not always. after turning the key on and off several times the car will start. this is a tdi by the way. if i don't get the glow plug light, it won't start.
front and rear light bulbs burn out too often