My 2003 A/C blows air sometimes cold air. Then sometimes hot air. Then it will go back to cold air. My warranty has expired. I am taking it to the dealership tomorrow - one technician says it could cost me $1,700 to replace the unit and another had mentioned that it could be a sensor that needs replacing or cleaning. This is a big difference in cost. Another tech had mentioned that the computer just may need to be reset.

These links may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1864159

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-11.html#post1999642

This last link may or may not apply to your car. You'll need to inquire whether your car has on-board diagnostic tests or not. If it does, it could save you a lot of money.