1986 300SDL: x-shape vacuum hose connector in trunk?
 

Looks like my vacuum pump in my 86 300SDL's trunk is on the way out. It sounds like it's dying a slow death and only working 5% of the time. While putzing around in the trunk I noticed an X shaped connector for the vacuum lines up the right side almost over by the fuel door. Weird thing is only 3 (yellow) vacuum lines were attached. There was one open port on the connector but for the life of me I couldn't find a loose vacuum hose. The open port doesn't appear plugged. Am I right there should be another vacuum line, totaling 4 lines, going to that connector? Thanks.

Can't remember exactly, possibly the X is supposed to plug in to the fuel door lock itself, is that possible? Or does one of the lines already run to the fuel door lock element?

Thanks Gilly. That was exactly it. Like an idiot I was staring right at the thing when it hit me like a brick wrapped in gold foil. :) Yeah, the open port was indeed for the fuel door pod.