All you need is to buy a intermittent wiper/washer switch and a intermittent wiper module and replace the wiper switch on the dash. Starting with the 84 model year, the wiper stuff went on the column. You can buy the switch from Chevy Duty and LMC for under $30, and the pulse module you can get from Year One for a little over $30. Sometimes you can find them on Ebay like I did. Hope this helps.
