Radio locked after disconnecting battery

You obviously disconnected the battery, your radio has to be re-coded. Loc means the radio is locked and needs a code to re-instate, did you buy the vehicle new? If not, maybe a different radio was fitted by the previuos owner

Sounds like the key switch has failed. Either the switch or the linkage between the switch and the lock cylinder.

I would suspect the ignition starter switch.

if you dont know the code i think you are gonna have to take it to a gm dealer..

you would have to remove the radio and post the chassis number of the radio

How to Reset GM Theft lock Radio's

Article Disclaimer: This article is meant to be used by Delco Radio owners to reset there radios. In no way is it meant to be used for any unethical or unlawful ways.

Purpose

The following instructions will allow you to reset any GM (General Motors), Cadillac, Oldsmobile, Buick, Pontiac theft lock radio.

Requirements

The theft lock radio must be in "LOC" mode.

Procedure:

1. Turn the ignition ON (The radio should display "LOC")

2. Hold down the Radio Presets 2 and 3 buttons for six seconds

3. The radio display changes from LOC to a three-digit number. Write this number down. You now have fifteen seconds to complete the next step.

4. Press the AM/FM button

5. The radio display changes to another three-digit number. Write this number to the right of the first one.

6. You now have a six-digit number, the first three digits are from STEP 03 and the last three digits are form STEP 05

7. Call 1-800-537-5140

8. Press 1 then # (pound). You'll hear "Invalid Code, try again"

9. Press 139010 or 106010 or 206010 or 202107 then # (pound). "it's really *<star>lol"
You will be asked to enter your four or six digit code followed by *

10. Enter the number from STEP 6 then *

11. Listen to the four-digit number and write it down. It will be repeated twice

12. Turn the ignition ON (The radio displays LOC)

13. Use the MN and HR buttons to enter the code from STEP 11

14. Press the AM/FM button. The radio display changes to "SEC". Your radio is now "un-locked" and usable.

Dealership Codes

* 139010
* 106010
* 206010
* 202107

Troubleshooting

If you fail to enter the correct code eight times, the radio goes into INOP mode. You have to wait an hour with the ignition on before the radio returns to LOC mode.

theft lock is an electric code that keeps the radio from working if the power is disconnected you must reprogram your code to work again if theft lock is not programed by the owner it needs no code to work if you are going to replace it with an after market radio it is mute any way

thats because its a key code security device once you disconnect its power source the radio will automatically lock itself to prevent theft but you can take it to a shop that sells radios and they can reset it for you but its impossible to diy because you need a computer to programme the microchip so take it to a shop m8 otherwise it wont work mine did the same hope i helped :)

Go to www.DelcoLockCodes.com and they can get the unlock code for your radio.

If the radio is displaying LOC then head on over to http://www.delcolockcodes.com and they can unlock it for you. I hope this helps!!!