i have volkswagen t4 transporter 1.9d , when i turn the engine off it runs on for a second or so. also my battery keeps discharging , but the alternator is fine, what could be causing it to drain.
The glow plugs could be staying on after the ignition is switched off. Glow plugs are basically little heaters to facilitate starting, they would help the fuel ignite and drain the power. Alternatively, there is usually an electrically operated fuel cutoff valve which stops fuel flow to the engine when the ignition is witched off, this is another possible fault.