E320 Cabriolet, locks after 20 seconds or so
 

Is this normal? It's a good thing I had a window down when I was testing my duo valve as it would have locked me out. None of my pre-94 W124's lock themselves like this...

I also notice the air pump runs for about 10 seconds after the key is switched off.

Has someone added keyless entry to it?
Gilly

If there is an aftermarket alarm or remote entry system then I would look into how it has been wired in.

You guys are brilliant or I'm a dolt...or both. I have an Alpine SEC-8447 key fob. The stock radio has a flashing light likely for the alarm and there's a mystery small momentary toggle switch in the cubby box. One more thing to fix or remove altogether...