Hi

My Octavia SDI 'glowplug' light starts flashing after the engine has been run for approx 20 seconds and flashes until the engine is turned off. From a quick search on the forums, similar symptoms point to a faulty foot brake light switch. However, the brake lights are working ok. The car starts and runs fine, there are no other warning lights illuminated.

My next thought was that the glowplugs are ON for the whole journey only going off after the engine is turned off, I guess that the flashing glowplug light is warning of this failure. This would point to a faulty relay that 'holds the electrical supply to the Glowplugs ON'. Does anyone know where this relay is?

Does anyone have any other ideas?

Thanks

Mark

The glow plug light doubles as the CEL and is basically the "something's gone wrong" light. Get the car scanned for faults.

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You can see the brake lights working, but how do you know that the engine control unit is getting the correct signal from the brake light switch?  It could still be the brake light switch or one of a few hundred things, you need to get it scanned.

As already stated you need to get it scanned.

If you've got a voltmeter, it will show a voltage from plug heads to ground with the engine running, if your glowplugs theory is correct.

As already stated there are a bunch of faults that can trigger the glow plug light to come on. Without a scan diagnosis is pure conjecture.