Two stage heat pump condenser only 4 wires

[Hvacgoon]

I only have four wires going to the heat pump condenser. Customer wanted two stage. How would I wire the condenser for two stage with only four wires?

[Sergroum]

1 wire common
1 wire reversing valve
1 wire compressor and 24v
1 wire 2nd stage compressor


my best guess without having ... any data really.

[Hvacgoon]

I have from the thermostat to the A/H six wires, but only 4 wires from the A/H to the condenser.

[Hvacgoon]

Running thermostat wire isn't possible either, customer doesn't want a ERM board cause the thermostat isn't the one she wants.

[Sergroum]

could you give us models?   thermostat, air handler, heat pump?

maybe pictures of the wiring at the thermostat? the inside of the heat pump and AH?

the setting I wrote earlier would work for some models.  I'm gathering it didn't? But now we'd need more data