hot-wire 
verb [with object] informal
Start the engine of (a vehicle) by bypassing the ignition system, typically in order to steal it: some of the children were hot-wiring cars...
- It was taken after a gang cut the padlock on the security gate and hot-wired the vehicle.
- Hot-wiring a plane, however, is easier than hot-wiring a car.
- Reports at the time included 50 cars being hot-wired and driven out of the showroom to be disembowelled for parts, and hundreds hospitalised after fires and fighting broke out.