My carrier heater give me the message that the wiring to the thermostat is wrong. Is there something else that could be the problem?

The LED code says "secondary voltage fuse is open"...

You have blown the fuse on the printed circuit board in the furnace, you might want to check the thermostat wiring for any bare wires or scuffed areas, look at the wires outside to the condensing unit, dogs like to chew on them.