Stereo Lighting up when Car is Off and Door Opens

[abaron]

Hi everyone,

Strange little issue that I fear will start to drain my battery.

I recently installed a Kenwood stereo in my 2004 Berlingo Desire 2.0HDi. All went fine, but I have now noticed that when the key is removed from the ignition, the stereo stays on. Similarly, when I turn then stereo off, and wait a moment before opening the door to leave, the lights come back on. Also, when entering the car as soon as you open the door, the lights on the stereo fire up.

I am able to turn the stereo off and get out quickly, but it's definitely annoying and if I forget, there's a chance it can drain the battery.

I'm as confident as I can be in my wiring, it was a simple Kenwood harness adapter and aerial adapter. 

If anyone has any guidance or advice, I'd love to hear it

Cheers,
Ali