If you mean the cabin filter it might be under the hood by the firewall right under where the winshield is it should say something like cabin filter or something.
There is no cabin air filter for a 1999 ford ranger xlt
which is the air conditioner relay on a 99 ford ranger
No
I was looking at the 1999 Ford Ranger Owner Guide and it doesn't show anything about it having a cabin air filter
No.
autozone.com has online manuals
Motorcraft FL-1A
Answering "Where do you add freon to your air conditioner in your ford ranger?"
On a Ford Ranger , 3.0 liter V6 engine : The engine oil filter is on the drivers side of the engine
its on the air filter housing
According to the Owner Guide and fordparts.com : Motorcraft FG-991 , is the fuel filter required for a 1999 Ford Ranger 3.0 liter flex fuel engine
You have a 1999 Ford Ranger 3.0.