The blower on our 04 Vibe runs very erratic. At first it would run when it wanted to and then it got to the point of when we'd hit a bump it would quit. Then it would start at will when you hit another bump. It got bitterly cold and stopped all together unless you'd hit the bottom of the dash on the side of the blower. Any ideas as to possible loose connection or how to test components or what to look for?