Shot starter?

Check the nut on the B+ lug, make sure it's snug and as always, check all connections. If you have a multi meter, check for proper voltage at the starter itself with the ignition switch on then when cranking, may be too much voltage drop over your pos. cable. With an assistant cranking, try to wiggle the wiring and see if it fires. If it cranks and starts then you have a bad connection/poor ground somewhere.

You can also try a couple raps with a hammer when trying to crank it over. windings may be missing connections. Replace starter.

Usually one click does mean the starter is toast though. If it buzzes/stutters it's usually the battery. Not always mind you, but probably a good bet.

Mini starters are relatively inexpensive. Just ask for one for a 5.2/5.9 Dakota. Roadside Auto Parts (now Carquest) on West Hills Rd. is OK.