98 Blazer Front Wiper not Working

I'm having typical problems with my wipers. I turn them on, maybe they'll work maybe they don't. Leave them on, eventually they start. Turn them off, maybe they'll turn off maybe they won't. I figured out if I place a plastic tie strap around the plug and the motor it self and clinch it down tight everything works like it should. That only lasted a year. So I did some research on this site and found the first recommended thing was to change the circuit board. That didn't help. Now I would like to check the wiring, but my Chilton manual doesn't show for the wiper system. Can anyone tell me what wires are for what, or have a diagram they are willing to share with me? Or any other suggestions for me to look at. I would like to get this done before the storm hits here in Detroit. I'm tired of taking chances during bad weather.

The two most common problems are the pulse board and dirty contacts in the multifunction switch. There's a thread in the Blazer "How-To" section that explains how to clean the contacts.