What I have learned through the years, of the automobile, selling, and trading is that all they need and needed is a little TLC and ELBOW GREASE. For example, all mechanical parts need lubricated with oils, and the electrical parts need to be cleaned and protected with some kind of contact cleaner! As for the vehicle in concern, I have learned that the (problem making 1998 Olds Bravada AWD 4.3 liter) that I own, most of its problems needed little effort to fix those questionable problems, meaning not having to replace the parts!!!
IF YOU KNOW HOW TO DO THESE THINGS, AGGRAVATION WILL NOT BE AN ISSUE DUE TO GENERAL MAINTENANCE!!! (that's a quote from my old auto instructor). Parts that were malfunctioning, I cleaned, and saved me a lot time and valuable dollars!!! Forums like these help people every day troubleshooting their automobiles.
Body bushings go bad causing incorrect alignments, such as doors not lining up, and causes rattles and squeaks!
Wiper motors malfunction due too bad bearings and rusty movable parts, which put electrical cir-cuts out of the manufactures tolerances and eventually over time will damage the electrical parts.
The Automatic Climate Control Panel is a tough task to tackle! It does not matter if it is new or used, the ACCP will not work properly if there air leaks in the vent ducts or if the windows are down. There are sensors in key areas of the vehicle that are constantly checking the cab temperatures! If any of these things are happening, the ACCP will produce false desired temperatures. My recent troubleshoot consisted of that, and I state that the (1998 Olds BRAVADA,that I previously own), I had no heat or A/C!!
In my General Maintenance procedure that I performed I noticed that air was leaking through areas of the duct work and discovered it was blowing onto the ACCP, (center of dash), (close to heater core),and considering it was chilly outside (34 degrees F), I concluded that the hot air was blowing onto the ACCP causing it to miscalculate cab temperature, so I got cold air instead of hot! I repaired air leaks around the duct work and reset system by unplugging negative side of the battery, for the standard few minutes, reconnected negative terminal and I'm riding with heat and air!!!