As others have advised, check the function of the climate control and take a good look at the servo. It's located under the hood near the firewall on the passenger side. If it looks like the photo below (aluminum body) then it is the upgraded version and the odds of a few years of trouble free operation are good.
If the servo looks like the next photo (plastic body) then it is more likely that you will have a failure sooner rather than later.
That all being said, I drove my SD for 10 years with a plastic body servo that operated flawlessly. When if finally did bite the dust I replaced it with an aluminum body version from George Murphy.