91 GMC Jimmy until now has run fine. Suddenly engine won't turn over. Lights work, battery has enough charge. Just hear a rapid clicking sound coming from engine when trying to start. Can anyone tell me what the problem is?

the clicking is a pretty good indication that the starter is either jammed or it is done. cure: pull it and get a new one. @-15mm bolts hold it up, careful it's a little heavy for holding it up, and you have 2 smaller nuts for the wires to pull, a 13 mm, and a 7mm, i believe.

happy huntin