Electric problem with car: Power stays on after turning car off

[El Gringo]

Just this evening I turned off my car (2000 Toyota Corolla), went inside and then came back out an hour or so later to discover that my radio, clock, and cigarette lighter still had power. Without the key in the ignition, I'm still able to listen to the radio, for example. This was never the case before. I had the battery replaced five days ago, but I doubt that makes a difference....Anybody got any ideas how I can fix this so that my battery doesn't drain?

I'm completely car illiterate, so talk to me as if I'm dumb. Because I am. :)

[Spork]

This is totally a WAG... but my first thought is that the ignition switch itself is bad.

...but this type of thing is rarely what I think it is.

[Milehimama]

We had this issue in our Dodge Caravan.  Sometimes I would take the key out and the engine would still run!

We used some electronics cleaner from Autozone on the ignition, sprayed it on the key and turned a few times to clean things up and it solved the problem.

[OOBER]

Also a WAG but it is the first thing that came to mind.

When you get out of the car and the radio is still on, try opening one of the other doors on the car. See if that makes the radio shut off.

What made me think of it is that most cars now days play the radio until you decide to get out of the car, if you had a bad door switch then the radio/power relay would never know that you got out.

Something quick and easy to try that would narrow it down some. Let us know what you find.

[Half-Borg]

Until you solve this issue make sure to disconnect the battery every time you life your car, or you will drain it and eventually break the battery.
Disconnecting and reconnecting the battery is usually a matter of seconds.

[El Gringo]

When you get out of the car and the radio is still on, try opening one of the other doors on the car. See if that makes the radio shut off.

What made me think of it is that most cars now days play the radio until you decide to get out of the car, if you had a bad door switch then the radio/power relay would never know that you got out.

No, my car has always shut off power as soon as I turn the ignition to off. I know what you're talking about - I think my parents' car does that, but not mine.

I'm guessing it's either the ignition switch isn't realizing that I'm turning it from ACC to OFF, or something in wires got crossed (no idea how) that is causing a constant stream of power to the radio/cigarette lighter, like it normally does with my clock.

Until you solve this issue make sure to disconnect the battery every time you life your car, or you will drain it and eventually break the battery.
Disconnecting and reconnecting the battery is usually a matter of seconds.

Yeah, I did that last night. It took a little more than a few seconds, because the bolts/screws on the clamps are somewhat rusty, it was dark outside, and WICKED ASS COLD.

[Greg]

As others have suggested, the most likely cause is a failed ignition switch.  Depending on the make and model, it can be easy or difficult to swap out.  As an alternative, you can install a quick-disconnect at the battery ground terminal, or put a switch in the ignition key-on power wire near the stock switch.  The best fix is of course replacement.

What year, make and model?

[El Gringo]

As others have suggested, the most likely cause is a failed ignition switch.  Depending on the make and model, it can be easy or difficult to swap out.  As an alternative, you can install a quick-disconnect at the battery ground terminal, or put a switch in the ignition key-on power wire near the stock switch.  The best fix is of course replacement.

What year, make and model?

It's a 2000 Toyota Corolla

[Greg]

Ah yes you said that in your original post, sorry.  The good news is the electrical part of the ignition switch in your car is likely a separate part from the mechanical key cylinder, which means slightly less hassle.  Are you mechanically inclined?  You can probably replace it.

Otherwise the quick disconnect at the battery ground is your cheapest, easiest bet.  Something like this:
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Battery-Disconnect-Switch-Universal-Top-Mount-w-Fused-Bypass/_/R-NW_785117_0282529017

But, if one part of the switch internals is bad, other parts may also soon fail. :(

[schimt]

there may also be a relay on that circuit that is sticking... A relay basically seperates high amp circuits from low amp control circuits. For instance fuel pump is controlled by the computer, the computer sends a low amp signal to the fuel pump relay which creates a magnetic field inside and essentially "flips a switch" to send power to the fuel pump. But the 2 circuits are seperate from one another when looking at current flow.

Usually the opposite is the problem and the relay will not turn the circuit on, but there is a change the relay is stuck in the closed position, or the "on position"

My vote would be the ignition switch though.

Good luck.

[Greg]

Another possibility is a faulty alternator.  The alternator usually contains diodes that when one or more goes bad, current can back flow from the battery through the alternator to the key-on circuit.  So, to test, unplug the harness from your alternator and see if the problem persists.

[El Gringo]

I got it to work today! There's a door switch (a little springy thing covered in rubber) on the door frame. It registers when the door is closed. I had to jiggle the switch. I have absolutely no understanding why this worked, because my car radio is supposed to (always has before and does again now) turn off when I turn the ignition off - not when the door opens.  Nevertheless, jiggling this door switch solved the problem.

(a mechanic who has the same car tipped me off to this).

Needless to say, I am not at all mechanically or car inclined, and this is the first time I have ever fixed my car by myself...even though it wasn't a difficult solution. :)

[schimt]

Glad it was an easy fix!

[Spork]

Woot!

I had a similar issue but in reverse: the ignition switch WOULD NOT WORK no matter what.  I pulled the whole steering column out only to discover it was just as simple:  a pressure switch on the clutch pedal.