So wife drives an old 2007 Pontiac Vibe. Kind of a beater but it just keeps ticking along (looking to get her a new car soon as I have too many old vehicles to keep tabs on). So 2.5 weeks ago I drove it with her grocery shopping, heat worked fine. Couple days ago I borrow the car and notice the heat absolutely sucks. It's a cold Minnesota day, 16 degrees outside. Think it over for a day trying to determine what's wrong. Tell me what I found......