My 03 2500HD wiper motor sometimes keeps running when I have them on delay andyou can't even turn them off.
any ideas on whats wrong and how to fix.
Thanks

 

Could be a bad switch or dirty contancts inthe multi-function switch (turn signal lever). Also look at possiblya bad connector in the wiring to the switch or maybe a cut/frayed wire in the wiring harness. Problem most likely inside the steering column at one of these.

 

Chevy has a small circuit board that controlls the wipers. It is not uncommon for them to overheat creating loose connections and intermittant problems similar to yours. You should be able to see discoloration or melted circuits if this is the problem. If you dont see any thing look elsewhere.