How?
I hear a padlock rattling somewhere nearby.
I’ll tell you, but only if you promise not to gun after my '94 Taurus Station Wagon.
Do I know how to? Yes. Is it a good idea to ask about illegal activities on a message board? Not really.
You cross some wires. Careful not to get shocked.
I used to do this all the time as a kid, sneaking my mom’s car out of the lot while she worked. Then one day I ran out of gas (I was broke, as always) and had to call her to have her call AAA for me. That stopped my career.
It’s harder these days, for the simple reason that people have steering columns that lock, so jumping the car does no good whatever. You can’t steer without the key.
But, let’s go back to the old days.
With a stick shift, you just needed a push, and the engine would turn over and spark itself, like cranking on an old Model T.
The other way was to put a screwdriver over the two contacts on the starter, just bypassing the key. If the conacts aren’t near each other, you use a wire. The wire gets hot, and if you aren’t wearing gloves you can really get hurt when it sparks. Plus, the fan roars to life, and the hood slams down.
I’m lucky I still have all my fingers.
What makes you think his intentions are illegal or that the gains achieved by doing that could only be negative? I hotwired a friend’s '94 Sentra today. It wouldn’t start. In fact, it wouldn’t even turn over at all. I had a sneaking suspicion that the starter and battery were good, so I made the necessary connections and fired it up.
I was right. Obviously, the starter was OK. The problem was a bad ground going to a relay between the ignition switch and the starter solenoid. Re-grounding the wire cost 10 cents for the connector. Far less than what she expected. She was ecstatic and I scored a nice, warm hug and a kiss on the cheek from a really nice girl. Any dishonesty or illegal activities there? I didn’t think so.
Another example: To make a living, I used to install car alarms and accessories, including remote starters. In order to be able to set up a remote start system in a car, you obviously have an understanding of how to hotwire the vehicle, since, in essence that’s what a remote starter does.
This is VERY much simplified and non-specific. In real life, there may be other wires to consider, plus, on moden vehicles, you have the issue of the steering column being locked. I am assuming, for my example, that the vehicle has a 12V negative ground electrical system. Other than that, no specifics. Please do not even think of trying this on any vehicle not belonging legally to you.
Either under the dash or under the hood:
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Locate a wire that is “hot” (12+) all the time. (thus the term “hotwire”)
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Locate the wire that normally gives power to the coil/ignition system.
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Locate the wire that gives power to the starter relay/solenoid to crank the engine.
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Make a constant connection between 1 and 2.
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Make connection between 1 and 3 long enough to get the engine started.
If you want more information than that, go take a course on automotive electrical systems, or look it up elsewhere.
Tried hotwiring a VW camper once (it was mine.) Worked, but in addition to the steering lock, the horn switch is closed without a key in the ignition so the horn sounded continously. Those car manufacturers can be sneaky!
Meephead basically got it right.
When you turn the key from the “on” position to the “start” position, the ignition switch is simply energizing the starter relay (a.k.a. “starter solenoid”), which in turn supplies voltage and current to the starter. So, in theory, all you have to do is figure out a way to either a) bypass the starter relay, or b) energize the starter relay without using the key.
To perform a), you simply need to directly bypass the relay contacts with a conductor. Note, however, that quite a bit of current will be flowing, so you should use very heavy copper wire. (Most folks use jumper cables to perform this task.)
There are two reasons I don’t like technique a): 1) You must use a heavy gauge wire (such as jumper cables), and 2) it produces an arc, and it’s never a good idea to produce open arcs under a hood in the vicinity of a battery.
So that’s why I like technique b).
To perform b), note that the starter relay (like all mechanical relays) has a coil. To energize the relay, you simply need to apply 12 VDC to the coil. Typically, one side of the coil is already tied to the chassis (common/GND), so all you have to do is directly apply 12V to the other side of the coil. This can be accomplished by connecting a wire between the +12V side of the battery and the coil contact. Note that, unlike technique a), you do not need to use a heavy gauge wire to energize the relay. Furthermore, it does not produce a nasty spark.
Either technique will probably work fine on older Fords, since the starter relay is bolted to the inside of the wheelwell. But it is my understanding that GM vehicles, in their infinite wisdom, decided to piggyback the starter relay on top of the starter. (Actually, the starter relay/solenoid is part of the starter actuator assembly in GM vehicles).
With all due respect andygirl, what in the hell are you talking about?
I can’t count how many times I’ve had to “hot wire” my car or a friend’s car because the starter relay went bad in the middle of a parking lot.
Geeze, people are really suspicious nowadays. How I long for the bygone days of innocence.
Nothing to add, advice-wise.
I had a 1973 Yamaha 100 Enduro that could be started by unplugging a wiring block (a square plastic connector with some wires in it) that lived under the left side of the fuel tank. The electricals (lights, horn, etc.) wouldn’t work, but it would start right up with the kick-starter.
I had a 1966 MGB. Being an MGB it needed a lot of maintenance. There was a button on the back of the starter relay (?) so you could start it or “bump” the engine (e.g., to get a cylinder to TDC) from the engine bay instead of having to be inside of the cockpit.
Nothing illegal at all about it.
My friend, who is a crack auto mechanic as well as computer god, once had his ignition switch die on him, and he quickly rewired it so his horn button would start the car.
It was surreal when I went out to his car the first time, and saw him press on the horn to start the car…