Help to get stereo code?

[SpartanAir]

I just recently pulled my stereo from my 1990 Pathfinder to put it in my President. I got it all wired up, I have power and sound, but after about 20 seconds I hear a beeping noise, about 20 beeps, and the stereo shuts off.

Is there a security code I need to input to make it work? I've looked into it and this looks like the issue but I can't find any codes online. Does anyone know how to get the code?

The stereo/tape deck make is Matsushita, Model no. 28115 86G15, serial no. 31940.

Any help is appreciated.

[Infinitiguy19]

If there is your going to have a tough time unlocking it, Try contacting the manufacture.