Doors Not Shuting Correctly

[win]

I have a 1996 gmc 1500 4x4 extended cab with 350 and auto trans. I just bought this pickup and it has 209k on it. This is my first gmc truck that I have ever owned.

The doors will not shut correctly with the windows up. when you roll a window down a little bit they will shut perfectly. Is their a cab filter or air presure valve that need to be cleaned out? The doors do not sag or wiggle up and down. I beleive the door pins and bushings are good.

thanks for the help

win

[Draenor]

Yes back of the cab.

[win]

Yes back of the cab.

 

is it behind the seat or under the seat?

thanks

win

[txab]

Behind the seat. You should be able to see the vents from the outside by looking between the cab and bed. All work will be performed from inside though.