u/Grant_A123

Hello everyone, new homeowner here. I’m looking for some help/advice on a pressure switch open fault that I am getting on my Frigidaire model FG7SC-090D-35C furnace. It has two pressure switches, one attached to the inducer motor and one near the bottom of the collector box near the drain port. I have narrowed it down to the issue being the pressure switch on the collector box. I don’t have any blockages on my exhaust vent as whenever I fire it up I can feel good flow on the exhaust pipe. I used jumper wires on this pressure switch and the furnace went through the start up process and fired up. I have cleaned the rubber hose, cleaned the ports out with a drill bit (by hand) and verified the pressure switch has continuity as I hear the click and see it on my multimeter whenever I suck on the hose to create a vacuum. I have even replaced this pressure switch, still not getting the furnace to fire up. I have taken off the inducer motor and cleaned out the collector box with a vacuum, and have verified water flows properly down to the drain through the collector box. I have taken off the rubber hose and can still not feel hardly any pressure coming out of the port for the pressure switch on the collector box. Is there anything else I can look into? I don’t want to have to call a service tech. Thanks.