I have a 1990 300D and the fuel door won't unlock. I pulled out the trunck liner and removed the amp (I think it is the radio amp). The fuel door lock has a round disk on the back and looks like I should be able to pull it to unlock the door. Nothing moves. Does anyone know how to unlock the door so I can get the locking mechanizim out so I can fix it?

Thanks
Dwight Hanson

I figured it out! To release the door you pull on the round disk on the back. It was stiff and I just pulled on it a little harded and it unlocked the door.

the fuel door [ unlike the other LOCK/unLOCK ] actuators uses vacuum only to LOCK the door. The unLOCK is accomplished by spring power. This is IF it works like the earlier models I have putzd around with.

Just making certain you understood how these function differently than the other 4 LOCK/unLOCK vacuum actuators !

Sam