I have a 93 F150 with an intermittent wiper problem. Sometimes they work, sometimes they don't. In the beginning, I could wiggle the multi function switch to get them to work, but now that is not the case. When they are not working, If I wiggle the multi function switch, I hear a clicking from behind the glove compartment (is that the module?), but nothing happens. Without rhyme or reason, they will start working. I can not find a pattern to the problem. I can not find a loose connection. I also can not find a good wiring diagram of the wiper circuit. Does anyone have any suggestions?

 

The clicks under the dash sound like relays switching or circuit breakers tripping. I removed the glove box and see a module there, but no relays or circuit breakers. And, of course, when I go to test the system, everything works fine.

 

That's the wiper control module.