Okay... I thought I had this whole trunk thing figured out, but I guess not. I cannot open it now. I know it has something to do with the locks. The last time I got it open I had to turn it 1/4 counter-clockwise and then lock the doors. Now that doesnt seem to be working. Anyone know how this is supposed to work? 1984 300SD

 

First, check the owner's manual. I know you must use the square key also, the round one is for the "valet" and he will not have access to your trunk or glove box with that key but will be able to drive and lock the doors. I think when the doors are unlocked and you turn the key 1/4 turn cc, as you stated, from horizontal, you can then remove the key and push in the button and open the trunk. I have only owned my '82 a few months and those tips work for me. My wife complains that it will not work for her but then again, a lot of things don't seem to work for her but magically work when I try them. Good luck, Steve

 

I guess my car is backward, because the only time I have been able to get it open is when I lock the doors, which didn't make much sense to me. I got it open again the other day. The last week or so has been very cold and my locks kept freezing up, so I was trying to open the trunk by locking the doors from the inside, but I guess I have to actually lock them with the key (???) or maybe I just finally used the right combination of swear words.

 

unless it is differant from my 82, with the key turned all the way to the left, then back to horizontal position the button will now open the trunk and the door locks will not lock it.
turn it back to the vertical position and it will only unlock with the power locks.
fun to figure out with the power locks not working!@*$&#
my owner's manual explained it to me.
my 79 300D has to have the key in the button for the trunk to open. not sure of the exact combination on it. I don't use it much.
John