97 Sonoma, 4.3L -- I had an intermittent wiper problem for a long time -- it seemed like every time I needed my wipers, ie. it's raining, they'd quit on me
-- a few weeks ago I removed 3 torx screws from the wiper motor housing exposing the back of the circuit board -- then I wrestled the board out of the motor housing and removed the wiring harness -- then I resoldered the harness pins to the connections on the board with some more solder and a solder pistol -- reconnected the harness to the board, inserted it back into the housing, and replaced the cover. So far, no failures when I need the wipers
-- I hope this helps - jack