I have a York Diamond 90 updraft furnace in the basement and it stopped working this morning.
I tried to troubleshoot the problem:
1. The DRAFT INDUCER MOTOR starts running but the furnace will not come on.
2. I see 3 flashes of the led on the control board which means that the pressure switch is open.
3. I saw that the pressure switch has two tubes connected, one to the DRAFT INDUCER MOTOR and one to the burner box, I checked both tubes connections, the one connected to the DRAFT INDUCER MOTOR is blocked by default (the motor side has the connection but when inserting a screw driver there I felt it's blocked) I looked at the other size connected to the burner box and cleaned it.
4. I briefly pulled the tube from the burned box and pushed air inside and the pressure switch closed.
5. The DRAFT INDUCER MOTOR is running as I can see.
6. I have two pipes from the furnace going outside, one connected to the DRAFT INDUCER MOTOR and the other to the burner box, from what I can understand the DRAFT INDUCER MOTOR pulls air from the outside through the burner box and relief the pressure from the from the other pipe ( am I correct), I cleaned both with vacuum cleaner, I felt strong suction from each side when connected the vacuum to the other pipe.

Where do I go from here?
Can it be that the DRAFT INDUCER MOTOR is bad and not sucking enough air from the outside?

The DRAFT INDUCER MOTOR is A165 Fasco