I have an 89 that my father in law purchased while on a trip to Florida in 1990 with just a few thousand miles on it. The reason it was for sale was probably because the AC just doesn't blow hard enough to really cool it down. The air temp is OK, but it just doesn't push it out. I replaced the fan motor several years ago when it went completely out, but that didn't fix this issue. He also took it to a dealer who declared it OK - is this normal for this model year?

Also, the windshield washer has always had such a weak stream that it only sprays under the wipers, not high enough to be on top of them.

Other than these issues, its been great - 253K with no major problems & runs great.

Welcome to the Bonneville forum.

Not sure how much this will apply to your year, but should give you a good starting point.
https://www.gmforum.com/t278997/

Have you tried disconnecting the washer tupe and seeing if it sprays good then? If so, the nozzles might be dirty. If not, the pump might be old and tired.