Joe, Having been a service rep for Buick in the 80's, my first question is does the car have any aftermarket anything???? The reason I ask that is because if it does have things like alarm system, remote keyless entry, remote starter, etc..... I would remove them all before I tried to do any diagnosis. There were/are a lot of extremely poor installations of that stuff that causes all types of problems and the problems increase where one of the modules go bad. Then if you go to section 8A in the manual, there should be a pin out of the fuse block to get you going.... but check for non factory wiring first and remove that first. Good luck.