I have 87 corvette that the after market stereo wants to kick on and off what could it be

a dead battery shouldnt need a new key made or recoded and the dead battery probably triggered the alarm because vehicle thinks radio was stolen recharge battery and clear computer with scan unit or remove positive side terminal for a few minutes and replace --and would question why a new key and recode was needed

If test light is a 12 volt light tester AND ILLUMINATES BRIGHT it shows that a component is actively trying to complete a circuit and yes drawing power causing a drain on your battery, now if test light illuminates low, possibility could just be ecm memory or antitheft system active . either way this test should only be done with a 12 volt test light as if you use a 5 volt (computer friendly) tester , false light will have you chasing a ghost. trust me. that trick helps by checking for parasitic draws a 12 volt tester does not illuminate when keep alive memory voltages are present . those voltages are not enough to drain over night. good luck

I’m happy to assist further over the phone at https://www.6ya.com/expert/james_9ddabbbc483e2add

1998 Chevrolet Corvette Car Stereo Radio Wiring Diagram
Radio Constant 12V+ Wire: Orange
Radio Switched 12V+ Wire: Yellow
Radio Ground Wire: Black
Radio Illumination Wire: Gray
Radio Dimmer Wire: Brown
Radio Power Antenna Trigger Wire: Pink
Radio Amplifier Turn On Trigger Wire: N/A
Front Speakers Size: 4? Speakers
Front Speakers Location: Kick Panels
Left Front Speaker Wire (+): Tan
Left Front Speaker Wire (-): Gray
Right Front Speaker Wire (+): Light Green
Right Front Speaker Wire (-): Dark Green
Rear Speakers Size: 6?
Rear Speakers Location: Rear Sides
Left Rear Speaker Wire (+): Brown
Left Rear Speaker Wire (-): Yellow
Right Rear Speaker Wire (+): Dark Blue
Right Rear Speaker Wire (-): Light Blue

I wrote a guide on the Corvette Forum for replacing the headlight gear, which involves taking the headlight motor apart and putting it back together:

http://forums.corvetteforum.com/c4-tech-performance/3194251-84-87-headlight-gear-replacement.html

Is this a deal or after market? If dealer item there are a copal of way to program. If after market contact the place you got it from and see if it requires special steps. Good luck

If the car is running after you crank it and keeps running until you turn it off and let it sit and the battery drains before the next time you crank it you should look for something left on maybe an interior light something you may have hooked up that does not turn off with the key switch this will drain it maybe the trunk light is not going off. or if the door stays ajar and floor lights stay on. Sometimes after market stereos have to be manually turned off if someone didn't hook it up right. If the battery needs jumping off right after you shut the car off then it is going dead and needs replacing.

Usually the blue wire from the stereo is for the remote amp and/or power antenna. If you haven't cut off the stock radio plug, I would check into getting a stereo harness adapter for the stereo. Most auto stereo shops can get them.

you can try bypassing it like this turn the key on then take a screwdriver and touch the 2 bolts on the starter try that or try changing the fender mounted starter selonoid

18436572

Hello If your vehicle has lost battery power, open the
hatch/trunk using the vehicle key. The key lock cylinder
is located on the rear of the hatch/trunk lid above the
license plate. Turn the vehicle key clockwise in the lock
That should get you in My dream Car LOL and Thank you for using Fix Ya Bear001