GE Z-Wave 4-way Wiring Problem

I’m trying to get three GE Z-wave 45609 and 45610 switches installed. My problem is the Neutral I need for one of the 45610 switches is tied together with a black line wire (just the two wires twisted together) in a dual gang box. If I untie those, connect the neutral to the 45610 and cap off the black line wire, I get no power to the 45609 switch (ie, blue light doesn’t light up when off). Can I pigtail into the line/neutral combo with the 45610 or will that ruin the switch? I’ve not seen a line tied off with a neutral before. Any help appreciated. Thanks!

It sounds like you are assuming the wire’s function based on color. You can’t do this.

You must positively identify the function and location of each wire in the circuit. Line, Load, Neutral, Traveler. You may be able to do this with the use of a voltage detector or a multimeter. If not, then I would recommend that you get an electrician or someone familiar with household electrical systems to do it for you.

Also, the title of this post is 4-way Wiring Problem. That would be three switches and a load. Is that actually what you are working with?

Thanks @Z-waver. Yes, I am working with three switches that control my porch lights. I will try with the voltage detector and multimeter.