Cadillac Repair: air ride 99 deville, air ride, test procedures

Question
I have a 99 deville that the rear end is sagging, how do you fix the air ride starting with the most economical.  Thanks

Answer
The most common failure is with the HEIGHT SENSOR.

If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL MULTIMETER, Simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.