how to change the AC filter on 2003 Nissan Altima

There is an odor when the AC is first turned on. We have had a very wet spring.

Asked by for the 2003 Nissan Altima
Cabin air filter is behind the glove box. Try replacing the filter, clearing debris and spraying Lysol or other disinfectant spray in the air ducts.
found the problem. mice had created nest on top of the filter. Thanks for the help.
1 more answer
Try to replace the cabin air filter if it equipped with one. There is a professional heater / evaporator box cleaner available from shops, which removes dirt and mold. Ask your shop if they offer this service.