 A malfunctioning AC system will leave you uncomfortably shifting in your seat, not to mention it can affect the safety and performance of your entire vehicle and your productivity. When issues with your AC system begin to occur internally, your truck will give you some warning signs. Those include a noisy compressor and a lack of water dripping from the cab drain tube while your AC is running. If you experience either of these warning signs, you should have your AC system inspected by a professional technician immediately.