Wipers will not work at times

Not a pro but had same problem on my truck. I was able to repair it by replacing the wiper motor. I hope this helps. Good luck.

Thanks Vetteslave for your reply and information, and is a starting point for me to begin checking. Hopefully it is not something buried in the steering column.

An update and possible fix for my wiper problem. Talked to a mechanic, he said most likely is the module that is a basically a circuit board that plugs into motor mechanism, and sort of the brains of the wipers. He said if wipers are not working, leave truck running, wiper switch on, and wiggle the plug fitting that is on the module, and if wipers start working, it is a faulty module. So wipers would not come on, went and wiggled the plug, and presto, they came on.
There are three torque head screws that hold a plastic cover over the module, once cover is off, wiggle the plug part of the module, and it will come right out.
Mechanic said modules run around $100.00, so I checked on the internet, and found a reputable car parts dealer on ebay selling new OE manufacture spec modules for $21.00 shipped. I ordered one and hopefully it is as advertised, and will cure my problem.
Should be here next week, and will post an update of the results of the new module.

Should have gotten back sooner with update, I received the module and was as advertised, popped it in and all is good. If you need a new module, shop around for the best deal, to save yourself some money. Changing the module is pretty simple, and an easy fix.