The system thermostat is calling for heat and nothing is happening at the furnace. The White Rodgers 50a50-471 control light is flashing 3-times and the code says pressure failure. I jump the switch out and the flashing light goes blank.

When you kill power to the furnace, wait a few seconds and reapply power, does the draft inducer motor run (with the stat calling for heat)?

No, I pulled the inducer fan motor plug and when the board cycles before the blinking light going out all together no power ever appears. I have the air pressure switch jumped out so I think the motor shouldn't be an issue. I'm trying to find out why the flashing light goes blank, as in no light at all after it cycles.

Thank you for your interest in this problem.
Syd