How do you troubleshoot the wipers on a 1999 Ford Ranger?

On my 99 ranger when the wipers started malfunctioning I had to replace the entire switch on the column. The part is easily replaced after removing the plastic shell covering the column. The steering wheel will not need to be removed, but I think the dash panel directly under the column will need to come off first. This solved my problem of random wiper activity. I'm sure there could be other problems due to motor failure or spline stripping. If the problem began when the wipers were activated while frozen I would seek another solution.