On a Chrysler the spec is .035 Amp or less. Other brands are similar. It can take 20 minutes for the computers to "time out".
You have a flat battery.
No, not unless the ignition is turned on.
Battery first. Will it start with a jump? Battery ok, then use a test light & see if you have current in the hot wire to solenoid when key turned. If you do, it's the starter. If not maybe the switch but start there.
The starter solenoid receives a large electric current from the car battery and a small electric current from the ignition switch. When the ignition switch is turned on, a small electric current is sent to the starter solenoid. This causes the starter solenoid to close a pair of heavy contacts, thus relaying a large electric current to the starter motor, which in turn sets the engine in motion.
Defective ignition switch, or bad starter.
Headlights run off the battery not the ignition...
It's possible that you have a bad ignition switch. Normally, those lights won't turn on unless the ignition is turned to the "Run" position. A bad switch may be allowing current to flow through one or more contacts when it's not supposed to.
The voltage reg is sticking and will run down the battery.
battery is shot?
The defroster is drawing more electrical current than the alternator can produce. It could be that the belt is slipping and the battery is margianally low so that when you turn on the defroster the alternator can't keep up and the battery isn't able to provide enough current to keep the ignition operating.
A person will have no power to the ignition when the key is turned over when the battery is dead or the ignition switch is defective. Each component must be tested to rule them out as a problem.
check the battery and connections/cables