Glow plugs, testing
WARNING: This page is about a different car, the 1996 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.
With the pre-glow system and extended glow period the current draw of each glow plug is a constant, approx. 8 amps, during the extended glow period with the engine running.
Current draw:
- 32 amps: all four glow plugs OK
- 24 amps: one glow plug malfunctioning
- 16 amps: two glow plugs malfunctioning
- 8 amps: three glow plugs malfunctioning
- 0 amps: all four glow plugs malfunctioning
The current draw can only be accurately measured when Battery Positive Voltage (B+) is greater than 11.5 Volts.
- Remove electrical connection and buss bar for glow plugs.
- Connect US 1115, VAG 1527B or equivalent voltage tester to Battery positive (+) terminal and connect second probe to each glow plug in turn.
LED lights up: glow plug OK
LED does not light up: replace glow plug