The mechanic at the dealership says that my '85 C-10, with intermittent wipers, needs a new pulse board. Is the board in the motor assembly or under the dash? Before I spend the big bucks on a new board, I want to look for a broken connection.
80's GM trucks had a silver coloured module under the steering column (has cooling fins on it) that controls the delay. It plugs in between the connector halves. If it was removed and the connector halves joined directly you'd have regular wipers. I just did that job on my '82 with '87 parts.
I also priced a new module b/c mine is acting all weird. They told me that there aren't many left in the system... price was a little over $50 Cdn.