How to Hot-Wire an Old Car (and Steal a Modern One)

You know what’s awesome? In crime movies when someone leaps behind the wheel of a car, kicks a cover off the steering column, mashes a couple of wires together and peels out. Hot-wiring a car is action-oriented, badass, and seems like something anyone could pull off. But what about in real life? I looked into it because I am interested in realism for my upcoming feature film (not because I want to steal cars), and it turns out that car theft is not as easy as Hollywood would have you believe—but it’s not impossibly difficult either.

Which cars can be hot-wired and which cannot

If you’re going to hot-wire a car, you need to pick an older hoopty/beater/bucket. The cut-off for hot-wiring is around the mid to late 90s. In later cars, alarms and immobilizers are pretty standard, and current cars have a variety of different theft prevention technology in place (more on those below).

A step-by-step guide to hot-wiring a car

Let me begin with a disclaimer: These are instructions for hot-wiring—starting a car without a key—not for stealing a car. There’s another process for unlocking the steering that I won’t be getting into that applies to most cars made in the last 50 years or so. Also: It’s potentially dangerous to go mucking around with your car’s wiring if you don’t know what your’e doing, so don’t. This is for informational purposes only.

The actual starting-the-car-sans-key process is easy to understand (in theory) and requires only a few simple tools, but it’s far from the 20-second operation you see in movies.

Tools needed:

And here’s how it goes down:

After you’ve thrown a spark plug through the window or used a coat-hanger to unlock the door, remove the panel in the steering column (in most cars) with your screwdriver. This should reveal a spaghetti-looking bundle of wires. You’re basically bypassing the key’s job of completing the circuit between the battery, ignition, and starter motor, so these are the three wires you need to find.

According to our sister-site Jalopnik, the battery wire is almost always red, and the starter wire is often yellow. The ignition wire could be any color, though. To find it, you could test each wire individually, but you’d be better off consulting the car’s service manual—I’m sure it’s on the internet, a library, or your local AutoZone.

When you’ve identified the correct trio of wires, strip off enough of their insulation to attach a clip. Attach a clip to each wire. (You could cut the wires, but why damage them?) Clip the battery wire to the ignition wire. Instrument lights and other dashboard things should come on, like you’ve turned the ignition key but not far enough to engage the starter.

Finally, touch the third wire to the clips (don’t clip it), and your engine should roar to life. You probably won’t be able to drive away, though, as you haven’t unlocked the steering. To stop the motor, unclip everything.

Stealing modern cars

Starting cars with alarm systems, key fobs, and other modern gimcracks is more complicated than stealing older cars, but it’s not impossible. There’s no universal method of hacking the starter/locks/alarm of every kind of car like there is with hot-wiring, but I assume any car’s security system could be defeated if you put in enough effort.

The main point-of-weakness in auto-security is the fact that there has to be a solution for a driver who loses their keys, so locksmiths and dealers generally have access to tools that allow key-creation easily, and it’s not like it would be impossible for an enterprising ne’er-do-well to get their hands on this tech and knowledge.

In many kinds of car, there’s a physical key contained in the key-fob, and it’s often connected to a code that allows a new one to be cut. Sometimes the code is connected to a vehicle’s VIN—so if you have the VIN and access to the car manufacturer’s database, you could, theoretically, cut a new physical key, unlock the door, and start the car. But you might not be able to drive away. You’d probably set off the alarm if you opened a car without using the fob, but once you’re inside the car, you could (theoretically) plug into the car’s computer and turn off the alarm system and pair a new fob with the car. (Real hacker stuff, right?)

Thieves have also reportedly been making use of relay devices. If you leave your keyless entry fob near your door, a device could transmit the signal to your nearby vehicle, allowing a thief to unlock the door, hop in, and drive away. They wouldn’t be able to start the car again, but once it’s parked far away, a cloned key could be made.

In summary: If someone wants to steal your car badly enough (or you want to steal someone else’s car badly enough), there’s almost certainly a way to do it. But in practice, many car thefts are more like crimes-of-opportunity: People leave their keys in unlocked cars, and someone takes off with them. This kind of theft accounts for a large (and growing) percentage of car thefts, so locking it up and taking your keys is as much as you probably need to worry about it. Life is short, ya know, and this is why we have insurance.