Blue series with no-neutral, dumb fixtures

Switches Wiring Discussion
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Hello all!

So I’ve got a Blue Series smart dimmer I’m trying to wire in to replace a dumb Lutron Caseta single pole switch. There’s no neutral in the box, and 5 dumb recessed LED fixtures fed by this switch. I don’t have specs on hand, but I’d expect each of the fixtures to be 10W or above.
When wiring the blue in and turning the breaker back on, it doesn’t power up - The LED bar doesn’t light up, and no button presses do anything. From what I glean from previous discussions, I might need a bypass?

On a more general note, there’s something I fundamentally don’t fully understand about this wiring scenario: if the switch is wired up to the line wire, which then continues to the light fixture, which is connected to the neutral on the other side - then shouldn’t the switch be able to be powered without a bypass?
The image in my head is that if I, hypothetically, replaced the light fixture with a wire, then the switch would be essentially be connected to line and neutral directly. Why would a bypass be needed, when the dumb LED fixture should allow current to flow if a voltage is applied? I apologize for my lack of understanding here, and I’d appreciate if someone with a bit more knowledge about this stuff could enlighten (see what I did there?) me a little.

Thanks!

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So in your switch box there are 2 conductors, exclusive of the ground. Did you test to determine which was hot?

What is the make and model of the five fixtures?

Not exactly, that would cause a short and pop the breaker. The non-neutral works because lights will leak through that switch loop, ideally enough to power the switch. But in some cases, there isn’t enough and a bypass (sometimes multiple) is needed to assist.

Double-check your wiring first!

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Thanks for the assistance! Correct, two wires plus ground (as they were connected to the dumb switch), and yes, I checked with a multimeter against ground and hooked the hot wire up to the corresponding screw terminal on the blue.

Naturally, my hypothetical would cause a short, I was just trying to illustrate the part I didn’t understand :wink: So if I get this correctly, the relay in the switch is off by default, so it can never power up because… the forward voltage threshold of the LEDs isn’t overcome so there’s no current and hence no power to the switch (I’m asking just for my understanding of the theory here)?

I’ve got a few bypasses in my shopping cart. Will I need one for each of the five light fixtures?

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Should only need one per light circuit*. If all 5 lights are being fed from this one switch, try one bypass at a light (I like first one in the path).

*some people required two.