Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hi. You could have a problem with a sensor or switch or the wiring for the ac to blow warm. But what is most common is to have a leak in the system and be low on freon. When the system is low on freon it blows warm. I suggest that you try to add more freon to truck and see if it starts blowing cold. If so, that will indicate you have a leak in the system.