Where is the filter on my 20+ yr old Goodman gu125-4
I'm fairly handy and I cannot find where the filter goes on my Goodman gu 125 furnace from the late 90s. Does anyone know if it is underneath or if for some reason it doesn't have one. Reason I ask is because it is not on the side middle or top or really anywhere on the furnace. It may be in the crawl space underneath the house but trying to stay away from there at. Trying 2 get this switched out because it's been a year so. Thanks any help or even a guide would be great