It does not have a cabin filter.
You do not list what year it is and expect an answer. All I can tell you is to purchase a Purolator Cabin Filter for your truck, as it comes with complete instructions.
2006 f150 xl cabin air filter location
this vehicle does not come with a cabin air filter
An 08 F150 Harley Edition does have a cabin air filter located on it. Furthermore, the F180 Harley Edition has a fuel filter located in the engine compartment.
I don't think 1999 F150 had a cabin air filter option. I have never seen an F150 with a cabin air filter, and all the guys around here I have asked have never seen one either.
It doesn't have one!
Purchase a Purolator filter as it comes with complete instructions. I think you will find that a 1998 F150 does not have a cabin filter.
It doesn't have an in cabin air filter for that year. There is an after market kit that can be installed to provide this feature if required.
Not much! Get a Chevy.. Trust ME!
It's behind the glovebox inside the HVAC case.