I messaged you a while back with some minisplit questions.

Hopefully I've explained this well enough - please let me know if you've got any further questions and I'll do my best to help. Thanks again.

Hello! Can you confirm that the control wires are on the correct terminals? It's usually ABC or 123 labelling.

The over-sized breaker may be an issue safety wise, but it wouldn't cause this issue directly. Double check with the electrician that the sizing is correct based on the installation. Typically if the indoor unit is working fine, but the outdoor doesn't come on, it's a power issue.

Yes, but also check the actual wire running directly to the compressor and fan. If the indoor unit is calling for heating/cooling, it should be operating and receiving power.

Sort of. You may not need to open it up, as you can usually look inside and see where the wires running to the compressor/fan are running to. Occasionally you'll need to remove an access panel to get to the wiring, but not always. It looks like you've got everything hooked up correctly, so this would be my next step - confirm that the unit is operating correctly. If it visually trace the wire from the fan back inside the unit, you'll see it connect behind to the L1-L2 area. Once you see where it is, you need to confirm it's getting power when the unit is calling for it to operate.

The reason for this check is you've said that the outdoor unit isn't coming on, but the indoor unit is. This way we can check to see if it's either a problem with the indoor head sending power/signal to the outdoor unit(or a programming issue), or if the indoor head is sending the power and correct signal, but the outdoor unit has something wrong with it. Confirming the fan or compressor is getting power when we expect it too is a logical place to start unless you're seeing something else with the unit? Does the outdoor unit come on in any combination of settings? Like heating, cooling, dehumid, etc?

Okay. It could be a control issue. You'd expect the indoor fan to at least spin up on heating depending on the outdoor ambient temperature. Just to confirm, This is only a single indoor head?

Okay - I'm not sure what the ambient outdoor temperature is where you are, but if it's warm enough for cooling, or cool enough for heating, set the unit to operate in one mode only. Then turn it on and set it to heat/cool. Give it 5 minutes, then check the indoor/outdoor head. Is the indoor head fan blowing, while the outside unit isn't? Or are they both off/on?