After disconnecting the battery radio does not shut off

hi Barb.
go to this link and it will show you how.
how to disconnect battery from car Google Search

Pull the kik panel off and disconnect the white wire from the button. Replace the button and connect the wire.

Ignition switch may be worn out or the safety switch on the transmission linkage when it is put in park may be bad ,

The battery itself may have an issue? You could try disconnecting the cable when you park and see if something is truly draining the battery. If it is you may notice a slight spark when you disconnect the cable. The alt may have a bad diode so it will charge the battery but drain it once the motor is shut off? Or it could be something like you suggested. The radio remembers its settings by being connected all the time. However a stock radio does not take much from the battery.

you will need a radio code for the radio to start working. This isbecause when you disconnect a battery the radio security system considers the radio to be stolen and goes into shut down to make the radio useless to any body with out the code.

Some radios need code after power been shut down or disconnected. Check you vehicle manual or go a Dealer to get the original factory code.

Hi,
Leave the battery disconnected overnight - NOTE THE ALARM AND OTHER BATTERY DEPENDENT ITEMS MAY NEED RESET, or just pull the fuse for the radio - read your owner's manual..
If it still doesn't reset, you'll need to remove the radio or see if it has a reset option on the radio.

GL,
Td

If car cuts off when battery disconnected alternator/regulator is not working.

A/C could be low freon level.

The headlight switch could be damaged but to disconnect the radio first as some radios that did'nt come with the car may be connected wrong and power is going from the power wire at the radio to the dash light circuirt feeding thouth it to the regular lights. pulling the cig lighter fuse solves the problem points you to this answer.

Some radios hold the codes for a few Min's.However ,Disconnect the battery again and leave disconnected for an hour.Then reconnect and Enter codes and confirm.Should work ok.