Okay, welcome to the forum! Let's troubleshoot this Lutron dimmer and companion switch setup. It sounds like you're very close, but something subtle is throwing it off.

Understanding the Components

Before diving into the wiring, let's ensure we're on the same page about what each component does: Lutron DVSCSTV Dimmer (First Switch)

This is your "master" dimmer. It receives the line voltage, controls the dimming level, and sends the control signal to the companion switches. This dimmer needs a neutral wire.

Lutron SC4PS-SW (4-way)

This is your intermediate switch. It has four terminals and reverses the connections between the two travelers.

Lutron SC3PS-SW (3-way)

This is your final switch. It has three terminals and alternates the connection between the common terminal and one of the traveler terminals.

Common Mistakes and Things to Check

Here’s a systematic approach to diagnose the issue:1. Neutral Connection at Dimmer (DVSCSTV)

This is the most common issue.

The Lutron DVSCSTV Dimmer requires a neutral wire. Ensure you have a solid neutral connection to the dimmer's neutral terminal. Without it, the dimmer cannot power its internal circuitry or communicate properly with the companion switches. Double check that the wire is securely connected to the neutral wire bundle in the box.2. Traveler Wires: Correct Terminals and Consistency



Carefully Verify Traveler Wire Connections

The traveler wires are the two wires (excluding the ground and neutral) that run between the 3-way and 4-way switches. They are the communication pathway. Double-check that the travelers from the DVSCSTV are connected to the traveler terminals on the SC4PS-SW, and that the travelers from the SC4PS-SW are connected to the traveler terminals on the SC3PS-SW.



Color Consistency

Ensure the color coding of your traveler wires remains consistent throughout the entire run. If you used red and black as travelers from the first switch to the second, make sure you're still using red and black as travelers in the same way between the second and third switches. If you switch them up, it will cause problems.3.

Line/Load at the Dimmer



Line In

The incoming hot (Line) wire must be connected to the correct terminal on the dimmer (usually marked as "Line" or "Hot").

Load Out

The wire going to the light fixture must be connected to the correct terminal on the dimmer (usually marked as "Load").4.

Grounding

Ensure all switches (including the dimmer) are properly grounded. A bad or missing ground can sometimes cause unexpected behavior.5.

Wiring Diagram Specifics



Diagram Accuracy

Can you post the exact wiring diagram you are using? Lutron has several diagrams, and we need to ensure the diagram you are using is the exact one for your specific switches and configuration.6.

Bypassing Companion Switches (Testing)

To isolate the issue, try bypassing the companion switches temporarily (for testing purposes only!). Connect the load wire from the dimmer directly to the light. Does the dimmer now function correctly on its own? If so, the problem is definitely in the wiring to/from/within the companion switches.

Troubleshooting StepsHere’s a good approach to narrow down the problem:1.

Visual Inspection

Turn off the power at the breaker. Carefully re-examine every wire connection at all three switch locations. Look for loose wires, frayed insulation, wires under the wrong screw terminals, or wires that may be touching each other.2.

Continuity Testing (With Power OFF)

Use a multimeter to test the continuity between the traveler wires at each switch location. This can help you trace the wiring and ensure the travelers are connected as you expect.3.

Voltage Testing (With Power ON)



Caution: Exercise extreme caution when working with live wires. If you're not comfortable with this, call a qualified electrician. With the power on, use a multimeter to check the voltage at each switch terminal. This can help you identify if you have power where you expect it and if the switches are switching the voltage correctly.

Posting Photos

If possible, post clear photos of the wiring at each of the three switch locations. This can be immensely helpful in spotting errors. Make sure the photos are well-lit and in focus.

Final Thoughts*The issue is almost certainly a wiring error, most likely related to the neutral connection at the dimmer or the traveler wires being connected incorrectly. Carefully and methodically checking each connection, using the above steps, will help you find the problem.Good luck! Let me know what you find. Flag for review