1999 I hear the compressor run it seems like every 15 minutes is this normal ? If not do I need new shocks ? If so where is a good place to buy them and can i install myself ? Thank you for the help !

Id say you got a leak somewhere. Unless you are corner carving alot then it might come on more. But more tham likely a leak.... need new shocks?

Before you go replacing the rear struts, there are a few other things to check.

One - O-rings may be a bit dry. Try putting some petroleum jelly around where the airlines hook into the struts, the compressor, and diverter valve.

Two - Check you ride height sensor. It may be a bit on the sensitive side. There should be a procedure in techinfo on how to check it.

Three - A crack in the line may very well be causing your leak. While unlikely, it is possible.