I turned them on for the first time from a new truck I bought, its was sitting for about 2 months and Im not sure why they won‘t turn off now. Even when its in the off position, they will change speeds for me but only two speeds work, I pulled the fuse out and blew on it for a sec to try and get the dust out then put it back in and it didn‘t do anything, I also wiggled the switch but that didn‘t do anything either, any suggestions to what I can do or what‘s the problem.
The problem with your truck is the circuit board controlling the wipers is malfunctioning and needs to be replaced. I had a similar problem with my 88 GMC and it's easy to switch out once you can locate a replacement circuit board.
The wiper delay module needs to be replaced, they are known for bad solder joints. It's attached directly to the wiper motor and easy to change. A new one will set you back about $50.00. If you are skilled with a soldering gun you may be able to repair the one you have. The joints in question are the ones that connect the circuit board to the wiring harness connector. Good luck.
If this has a combination switch that you use for your turn signals,bright and dim your headlights and so forth it would be the contacts in the switch that may be burned out and causing the problem.The contacts are in the top of the column so it would have to be taken apart to replace the switch.
