Have a 8 year old Rheem furnace , should the wiring to the thermostat mimick the wiring to the furnace controls? The a/c works but when I turn on the heat the inducer motor turns on (recently replaced , but it does not cycle or ignite.

When the unducer fan motor turns on do your hear the pressure switch click? The pressure switch will be connected to the inducer motor by a rubber hose

You may not necessarily hear the pressure switch 'click'. Some are louder than others. One thing to keep in mind about pressure switches is that unlike other switches, if they fail in the closed position the furnace sense it on a call for heat and will not ignite. This is a safety feature built into the circuit board.

Does the igniter glow? These hot surface igniters are very fragile and even a hairline crack and it is useless. Do you hear the gas valve open?