I have a 02 Nissan Altima that is constantly having heating problems. I have brought my vehicle to the dealership 4 times in the past 16 months and they still have not resolved the issue. Any advice?

See if this link helps:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post235973