Delco is the manufacturer for car radios and parts on General Motors (GM) vehicles like Chevrolet, Buick, Pontiac, GMC, Cadillac and Oldsmobile. Your Delco radio comes with a hidden antitheft feature. It locks down when the power is lost or your car's battery dies. This feature prevents thieves from operating your radio. Since Delco created your 15850275 RDS after the year 2000, you probably have come across this feature. To unlock your Delco radio, you need to obtain an unlock code. You can obtain the code from Delco or your GM dealer.
Hold down the preset buttons 1 and 2 for 10 seconds. Wait for a set of 2 to 3 numbers to display on the screen. Write down the numbers.
Press the "AM/FM" button. Wait for another set of 3 numbers to appear. Write down these numbers as well.
Contact Delco at 800-223-3526. Ask the representative for an unlock code. Provide the model number and serial number, located underneath the radio. Alternatively, you can call your GM dealer for an unlock code.
Press the "MIN" button. Wait for the screen to display the last 2 digits of the unlock code. Press the "HR" button until the first 2 digits display. Press the "AM/FM" button to enter the code, using the keypad.
Wait for the radio to display "SEC." This means you have unlocked it.