In the event of an electrical short-circuit and cabin fire in a commercial heavy truck, what is the driver's first immediate mechanical action after stopping safely?

1. Turn off the engine ignition key and switch off the main battery master disconnect switch (coupe-batterie / coupe-circuit)
2. Pour diesel fuel on the dashboard wiring to smother sparks
3. Accelerate in reverse to blow smoke away from the windshield
4. Open all windows and turn the cabin heater to maximum