The pressure switch by-pass did not turn on the ignitor. the vent is clear, and the centrifugal fan is creating lots of air flow. the LED for the "Y" connector is now flashing 3 times and then a pause.
Checked the limit switch. shows continuity. light pressure on the limit switch disc opens the circuit. Put every thing back together. Still have 3 flashes on LED at "Y" connector and the main blower motor comes on as soon as power is applied. The vent motor also comes on. Shouldn't the vent motor come on first followed by the ignitor and then the gas valve and then the main blower motor after heat is established in the chamber that collects the heat for distribution?
We hit paydirt.
That was it.
Everything is working in proper sequence now with that limit switch by-passed.
Is there anything else you can think of that I need to do other than replace the limit switch?
Thank you so much for the expertise and patience you displayed.
You are a credit to your profession.
I have already taken it out and ordered one.
I shut the furnace down once I saw what the trouble was.