Drivers front and rear speakers will not work at all. on 1996 GMC Yukon

Both front and rear speakers on driver's side will not work at all...How can I find out why without having to take the whole dash off? Please any help will be very much

Asked by for the 1996 GMC Yukon
check your speaker balnce to start
I have checked all the out of the door type of things that could be wrong. But I was kinda hoping that it might just be a lose wire..I cant seem to find any diagrams for the wiring for speakers. However the front
and back do not work so makes me think that side may be unplugged..possibly. What else could be wrong with just one whole side?
Thanks for your help.