Vacuum hose placement

1999 s-10 drivers side. Can someone tell me where this hose connects. I have a very rough idle and rough ride all through the rpm range. I took a look under hood and heard a sound from this hose, I put my finger on the end and it has a vaccum for sure but no idea where it hooks on at.

http://home.comcast.net/~ftgfloors/cl/hose.jpg

It's a vacuum hose that's connected to a plate mounted on the driver side fender. It may be a bit difficult to locate, but it is there. It controls the MODE selection knob on the computer climate control (if you have it). Are you having any hvac problems as well? This will fix that problem. However, I'm not sure if it has anything to do with a bad idle or rough ride you're having.