i just put in an aaftermarket cd player in my 88 420 SEL. i have 2 problems. 1. i can get my door speakers to work :( and 2. every time i LOCK my car, my alarm goes off. yes i said LOCK. :x im going to do some fenangling to get the door speaker to work, but i have no clue how to fix the alarm.

I am in teh same boat as you sorta. i have a '87 560 SEL and after installing my after market radio the alarm goes on all the as if my old radio was stolen and anitheft alarm goes off. Also i dont know if this has anything to do with it but the SRS light in teh dash goes on and so does the radio when i open my door. Any help would be appreciated. Thanks

i was able to counter the alarm by: when i lock it, i turn the key all the way very quickly and take it back out just as quick. it takes a lot od finess, but its do able. my alarm chirps but doesnt go off. reguardless im still having a hell of a time getting the dorr panels off to get to the door speaker.

if its a different problem, maybe the guy who installed it didnt connect the alarm wire or ground it. the guy i had do it for me hard wired it. he had a hell of a time doin it, but it works great.