Several possibilities come to mind with that description: You COULD have a bad solenoid or starter, you COULD have a bad keyswitch, you COULD have a bad battery connection that needs cleaning. I'm certain there are numerous other possibilities that could account for what you describe, these are just the first things I would look at. If you have any other information on the subject post another question and I'll put this on a watchlist.
More than likely you have corrosion at the terminals. Clean the battery terminals and then recharge the battery and see what happens.
It could be a bad battery, or connection. A bad starter and or solenoid could be the problem, along with an ignition switch to name a few.
You could accidentally short out the power wire to the radio and blow a fuse. But you really do not have to disconnect the battery terminal. Just remove the fuse for the radio circuit and you will be fine.
you either overlooked a hot lead that needs to be reconnected at the battery, or you grounded a hot wire and blew a fuse or fusible link wire
once a battery is connected even if the key is not in the ignition, there is always power at certain points in your car. Connecting a battery backwards will not start your car, but it can and will fry the wires to your starter.
Low battery voltage? poor battery connections?
This happens a lot. We finally figured out to disconnect the battery and wait 20-30 seconds. I actually heat a "click" in the steering wheel/ignition area in the car and the key works fine.
The battery does not work.
the battery will leak
your battery is probably dead...., if when you turn the key and nothing happens at all...your battery is probably dead... Solution: Well, it turns out it was my ignition switch. That was my first guess. Im glad i went with it.
Towing will not damage your ignition switch.
The battery will explode.
Possibly the ignition switch is defective.
If you operate any electrical device even turning on the ignition, you risk burning out any diodes.
If you don't disconnect the battery when installing gauges, it is possible to create a short circuit and blow a fuse. Some gauges have power present even when the ignition switch is turned off.
It's what happens when a battery is about to expire.
Depends on what kind of battery
It will destroy the battery.
The ignition system is powered up and ready to run the vehicle.
with a fully charged battery and clean connections to the starter and battery check fuses first and if good, replace ignition switch under steering column
The battery becomes hot
You will ruin the battery.
Is the car in park? Do the lights turn on? If so are the dim, or bright? If no lights you likely have a dead battery. From there I would check fuses. Good luck.
Yes. If you disconnect the battery from the vehicle what happens is that the anti theft system on the radio thinks the the radio is being stolen because it loses power. What you have to do is enter a code that is provided to you by the dealership. If they don't have the code on record then the dealer has to remove the radio to find out the code.