Ok I know what you are going through I had the same problem with my 1993. Oen the compartment that holds your jack it sould be in the back on the driver side. Tack the jack out and all the hard wear to it so you can get a good view of the inside. If you look in the opening towards the front (useing a flash light) you will see a little black computer. With the truck running as you looking in the opening on that computer there should be a little red light lit if it is not lit then you need to go to a junk yeard and get a new one coz that means it is no good. It only tacks about 30 min. To tack it out and put the new one in. If you have any problems just email me asap and I will give you my cell number and talk you through it ok.
p.S. My email address is eckerson17Yahoo. Com