windshield wipers

in my jeep the delay on the wiper switch doesnt all the time. some times when im least expecting it the delay will work. i thought maybe a bad switch? i will probably replace that after i find a junkyard round here that has xjs

the 93 has a delay module velcrod under the dash above the drivers left leg area. either the module has a loose connection or it is starting to go bad. thats the most common problem.

What about for the rear wiper?