take the door card off look where the handle is should be ether 3 to 4 ten mil nuts take the nuts off with anything else that is attached the replace and do everything back wards
Cars are heated by the water from the engine. There is a small radiator under the dash that is used to warm the inside of the car. If the valve that let's the water flow through the heater doesn't open then you won't have heat
Yellow means you are approaching the maximum RPM allowable for your engine; red means you have met or exceeded the engine speed that is factory determined to be safe for your engine.
It is most likely your connection. If you have a multi meter check your power supply to the motor. If it has power replace the motor. Because it is bad.