Mystery Tick from Becker rely
 

Mystery ticker
This is an 89 300e. New to me – still in the check out stage. So suddenly the other day I hear a relay ticking, and find that it is blinking my lights – low beams and running rears. I see some aftermarket wires and think it must be part of some aftermarket alarm system that was not disabled completely, but no. Under the passenger floorboard I find a Becker autosound box. It begins ticking whenever I apply brakes, open a door and blinks the light for 2min 15 seconds then shuts off.
Unless this is some way connected to a alarm system or something, I’m stumped. The radio does only comes on, on it’s own schedule and shuts down whenever any button is pressed. It does automatically power up, but no sound. I’m going to replace the radio, but now finding this mystery box has me backing off until I know what’s going on.
Also is the 8 pin connecter only a code reader or is it more involved?

Answered my own Q - Just locked and then unlocked the door. Now, how did it get armed on it's own?