Forgive the double post, but I believe that this is the circuit you're trying to achieve...
You had the lights positioned between the fans, rather than around the fans. Electricity will follow the path of least resistance, and ignore all other paths. So, when you have a solid path and a path with some sort of resistance (the lights) the electricity will always take the solid path. When there are two paths that take the same amount of work, then the electricity will follow both. Now, in the above design, the switches are positioned so that the fans have to be on in order for the lights to be on. If there is a particular night that is a little cooler and you want the lights on, but not the fans, this design would work better...
In this design, the switches are on their own paths and operate independently from each other. So, you can have the fans on, the lights on, or both.
Now, all this is not even taking any necessary resistance into account, but I assume that you're going for basic conceptual design rather than figuring out a detailed circuit design. I hope this helps.
Edit: I just noticed that you got offline recently. I really hope you see this before you try to build your circuit.
You had the lights positioned between the fans, rather than around the fans. Electricity will follow the path of least resistance, and ignore all other paths. So, when you have a solid path and a path with some sort of resistance (the lights) the electricity will always take the solid path. When there are two paths that take the same amount of work, then the electricity will follow both. Now, in the above design, the switches are positioned so that the fans have to be on in order for the lights to be on. If there is a particular night that is a little cooler and you want the lights on, but not the fans, this design would work better...
In this design, the switches are on their own paths and operate independently from each other. So, you can have the fans on, the lights on, or both.
Now, all this is not even taking any necessary resistance into account, but I assume that you're going for basic conceptual design rather than figuring out a detailed circuit design. I hope this helps.
Edit: I just noticed that you got offline recently. I really hope you see this before you try to build your circuit.