Glow plug system, checking: Conditions

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Volkswagen Jetta, 2001 Volkswagen Golf, 2000 Volkswagen Jetta, 2000 Volkswagen Golf, and 1999 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.