Odd electrical issue

I'm at a lost here. I have a 99 Chevy Prizm and if I push the cigarette lighter in the front window wont roll down...........but it only happens sometimes. My battery terminals keep corroding and the battery is only 6 months old. I have had to clean the terminals 5x in the past 3 months. What should I start checking

Now to add to this odd issue my check engine light just came on. I'm getting p0441 Evaporative Emission Control System Incorrect Purge Flow...........so I'm wondering if this could be contributing to my other issues, maybe loose wiring?