Ok this the deal I have a 2003 Pontiac Grand Prix gt with wiper blade malfunction, it don't want to work in the mornings when I need them but after the day warms up they work like nothing ever happen.
I would check the electrical connection. We all know that when metal or rubber (the wiring casing) expands when warm, and contracts when cold. If there is wire loose or not fully grounded, it can cause this issue. Best of luck!
You can locate the wiper motor (usually located under the vents (below your wipers) in the engine compartment. Hope this helps!
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts