Me Again;2002 SONOMA 4X4
My defog lacks air flow. I was told that there might be an air filter just for the defog. Is this true, and if it is, where is the filter located? My heater works fine. Lots of air flow, just not the defog.
Thanks

Some newer trucks have a cabin air filter.
But it does not just kill defrost.
Check parts place and see if they show one for your truck.
Owners manual may help you with the location of it.