Is the steering locked ? If the steering is locked, how can you turn?
Down at the starter motor, there are two wires ,at least.
A big chunky one, running straight from the battery.
Leave this alone, it carries the large current to drive the starter motor.
A small one from the ignition. When this wire supplies 12 ( or 24 ) volts into the starter motor, the starter motor operates. A solenoid powered switch connects wire 1 to connect to the actual starter motor inside. Its a relay but not being a discrete package, its called the solenoid (of the starter motor.). The reason for the complexity is so that the huge current doesn’t have to run through the switch at key… The key would be too heavy to turn !.
There may be a third wire, eg a ground strap or something.
The interesting one is wire 2.
I know that when you operate the key and move it from “on” aka “ignition” (where it sits when driving… ), to “start”, two effects happen
A. All features to do with running the engine the engine remain turned on - this means the fuel pump(s), the injectors, the ignition (spark plugs), the computer,
and you can extend this to any other system like variable valve timing , of course… “start” means the engine will start. I figure throttle and automatic transmissions will also be operating .
B. BUT all the accessories, including head lights, all things “dashboard” , indicators, are definitely off. And perhaps other things like engine cooling fan, ABS/stability controls, electric power steering, perhaps are NOT turned on ! And that means using the starter motor’s start wire is not enough. (Also if it was, it may not be big enough to power other features, such as air conditioning fan.)
Point A. means that that if you remove the wire 2. from the starter motor, join it up to the +ve the battery, the engine is ready to run, and then touch it back to the starter motor terminal to start the motor, it will start. You could drive it.
Point B, what you didn’t mention, means its still not safe to drive. You’d also have to connect +ve from the battery back to one or more placed in the dashboard circuits.,
eg to the fuse box terminals , or to the +ve of the air conditioning fan
The key might drive a couple of switches, so there may have to be more than one wire to the dash area … as the circuits don’t connect back together at the same terminal at the key mechanism… Also the headlights and air conditioning fan may draw a large current, so be careful your temporary jumping doesn’t power them through a too small conductor.