Hello I am here to assist you.
The inducer fan motor is located inside the furnace cabinet and is connected to the flue vent pipes. It has a rubber hose attached to it that connects to a round pressure switch.
Locate what I just described and let me know when you find it. You will have to remove the top furnace panel to locate.
Are you able to take a picture of your furnace and attach to this chat? Just use the tree symbol?
The tree symbol is what allows you to attach pictures to this chat I beleive.
The furnace is verticle as seen in the photo. Hopefully you can show me what to do.
Do you need any other pictures or different angle?
Due to this furnaces setup, you will have to call a technician out to repair it.
The problem is that the inducer fan motor and pressure switch connections are clogged. In order to clean them, the inducer fan has to be removed and possibly the entire back panel so the connections and hoses can be cleaned out. Unfortunately this requires the knowledge of a skilled technician. I would advise you not to try this.
The clogged hoses and connections are preventing the pressure switch from closing. And also you possibly need a new pressure switch as well.
On newer models , I am able to walk customers through cleaning these components. But on this older model, it is too complicated.
Please hit ACCEPT if you are satisfied with this answer. Bonuses and positive feedback are very much appreciated!