Old one has the standard Y, G, and Y,

Then there is a W1 and W2 don't know where to put them

This is just a plain jane furnace with an aftermarket central air unit,

Everyone is telling me it must be a heat pump or two stage unit... I highly doubt it.

Thanks in advance for any help.

I meant R, G, and Y,

R is for power, g is for fan, y is for cooling, w1 is for heat. The w2 should not do anything

You have 6 wires hooked up now?

you have 6 wires hooked up now?

No 5

The old thermostat also Montgomery Ward has R, G, Y, and W1 and W2

W1 and W2 if I follow them to the furnace they hook up to a transformer labeled W1 and W2

The R G Y all hook up to a second separate transformer inside the furnace

It looks like in the old thermostat that W2 jumps back to R via an internal switch that looks like it never moves?

I will try without W2 and see what happens.

That's what I would do first. Then let me know what happens.