Final answer:
The main function of an ignition safety switch in an automobile is to prevent the engine from starting without the key being inserted into the ignition.
Step-by-step explanation:
The main function of an ignition safety switch in an automobile is to prevent the engine from starting without the key being inserted into the ignition. It acts as a security measure to prevent unauthorized individuals from starting the vehicle. The switch is typically located close to the steering column and is connected to the ignition system.
When the key is inserted and turned in the ignition, it completes the circuit and allows electrical current to flow to the ignition system, which then starts the engine. If the ignition safety switch is not engaged or faulty, the circuit remains incomplete, and the engine will not start even if the key is turned.