$10k Nightmare solution

[Frog Monster]

Light switch 1 turns light on/off, always works regardless of motion.
Motion sensor switch 2 turns the motion sensor on/off, light switch 1 still works regardless.
Motion sensor only works if motion sensor switch 2 is turned on.
If light switch 1 is on, the light stays on. Light light switch 1 is off, but motion sensor switch 2 is on, light will go on/off by the motion sensor.

[IkeaGnome]

You have it drawn up as series circuits with light switch 1 being the first and last stop for power from the mains. 
In your diagram light switch 2 also completes the circuit to and from mains for the motion sensor. 
 

Edit: light switches are in parallel, light switch 2 and motion sensor is series. From your post it sounds like it’s working like it should based on the diagram. 

Edited May 29, 2022 by IkeaGnome

[Frog Monster]

I'm not sure the problem you are suggesting. Light switch 2 does not turn the light on, it just turns the motion sensor on. Then the motion sensor is able to turn the light on.

Nothing is wired in series there, everything is parallel. Still not sure what you are talking about.
Edit: I don't see this series thing this guy is talking about, but to Linus: If you are considering using this as a solution, everything should be wired in parallel, and have a professional do it.

[Electronics Wizardy]

Why not get a three way switch? That's the normal way to wire up something like this. 

 

I'm pretty sure this exact plan would be against code as you can't switch the neutral, just the hot line. But I can't find any reference for this in the code or online so its gonna be a pain to get past inspections as it's not a standard wiring method. Id guess it would fail inspections as the switch could be hot even with that switch flipped off.

 

 

[Frog Monster]

I'm not sure how it would be hot when flipped off. I also don't know the code, but that's why I said hire I professional. This is just for illustrative purposes. A 3-way switch would be fine too, but it would not allow you to manually turn the lights on/off while the motion sensor is active, it would have to be one, or the other, or off..

[Electronics Wizardy]

2 hours ago, Frog Monster said:

I'm not sure how it would be hot when flipped off. I also don't know the code, but that's why I said hire I professional. This is just for illustrative purposes. A 3-way switch would be fine too, but it would not allow you to manually turn the lights on/off while the motion sensor is active, it would have to be one, or the other, or off..

If you have the motion sensor powered, but the light is on, and you work on the bulb/switching thinking its not powered, you could trip the motion sensor and have it hot

 

A 3 way switch would let you change the light being on/off from either switch. No matter how the switches are flipped currently, flipping either switch will cause the light to change state.

[JogerJ]

This looks so complicated. Can't you just connect some relays and call it a day? 

[Frog Monster]

1 hour ago, Electronics Wizardy said:

If you have the motion sensor powered, but the light is on, and you work on the bulb/switching thinking its not powered, you could trip the motion sensor and have it hot

 

A 3 way switch would let you change the light being on/off from either switch. No matter how the switches are flipped currently, flipping either switch will cause the light to change state.

If you have the motion sensor on, and the main light switch on, the light would remain on. Light switch 1 is the "master switch", if it is on the light stays on. Switch 2 turns the motion sensor on, but if switch 1 is still on, the light always stays on.

Edit: I have watched a bit more of the show now, and it seems Linus is planning to do almost exactly this anyway. A "dumb" switch+motion sensor of some configuration, which he has a professional electrician on standby for. In current year, sometimes the smartest solution is the "dumb" solution.