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Is it okay to leave the key in Run position without starting the car?

My husband likes to turn the key to the run position instead of the accessories position to engage items like the radio or fan.



I’ve been told that this can burn out the starter (or other car components?). But that may be an issue with much older cars as I learned this many years ago and I’m no longer a Spring chicken (maybe not even a Fall chicken).



He thinks there’s no difference between leaving the key in the run position (car not running) from leaving it in the accessories position, and he thinks there is no damage being done to any of the car components, including the battery.



I will note that on his 2003 Accord he got a dead battery ages before I needed to replace my original 2002 Passat, slightly weak, battery. I should also note that he never turns his headlights off and lets the car automatically turn them off for him…so maybe that’s why his battery died prematurely.

It will run the battery down more quickly because several things (like the engine computer) are being powered that don’t need to be. I wouldn’t do it, but it is unlikely to actually harm anything, other than the battery running down.
(On older cars, it wouldn’t burn out the starter, but it might burn out the ignition coil.)

NOT a good idea as the ignition system and fuel pump are energized and the battery will be run down quickly…

You are right and your husband is wrong…but try not to let it go to your head. There is a difference between the two key positions. However, the fan probably won’t run with the key in the accessory position, so he may have a good reason for doing this. However, I would not do this. I would open a window instead.

Not on a 2002. The fuel pump turns off after a couple of seconds, and the ignition coils are not powered until the engine starts turning.
The various computers will stay powered the whole time.

Using the “on” position rather than “acc” on an '03 Accord is not a problem. It does use more current, but for short periods should not run down the battery.

In older cars some electrical ignition parts could fail as a result of this practice. I burned out the ignition module on an '85 Ford LTD midszie wagon by leaving the ignition on by mistake.

Is it a good practice to do this, no. Is it harming his car, no. Did it cause the battery on his car to fail quicker than yours?, not likely.

If you want to keep arguing about it by all means go ahead.

On old cars, there used to be two electrical contacts called points that opened and closed very quickly as the engine turned to send electricity to the coil to generate the high voltage to fire the spark plugs. If the engine happened to stop while the points were closed, when you turned the key to the “run” position, the coil would be directly connected to the battery and if left that way for a few minutes, the coil would overheat and be ruined.

Cars haven’t really had mechanical points since the mid-70’s, though, so he’s not going to imminently damage anything, but I’d agree with the other people who say it’s probably not the best habit. They provide the accessory position for a reason.

VW’s used breaker points into the 70’s. If you left the key on the coil would get very hot but thats about all that would happen. I have left keys on overnight with no problem (other than with the boss).