Hayward ColorLogic Light Not Turning On
Quick Summary
- A dead ColorLogic light is almost always a power delivery problem: tripped GFCI, absent 120VAC on the transformer primary, missing 14VAC on the secondary, or a bad junction box connection.
- If the light is being controlled through a switch, controller, or automation system, confirm it is actually being commanded on before measuring voltage.
- Isolate each light individually — if one works and another doesn't, you have a failed light or a localized wiring problem, not a transformer failure.
- If using a 300-watt LTBUY11300 transformer, the 14VAC output only appears when the blue and white wires carry the load — verify correct wiring before condemning the transformer.
Understanding Why a ColorLogic Light Goes Dark
Hayward Universal ColorLogic lights are low-voltage LED devices that require 12–14VAC delivered to the cord's junction point. They get this power from a step-down transformer that converts 120VAC to 14VAC on the secondary side. If anything in that chain fails — the 120VAC source, the transformer itself, the low-voltage wiring, or the junction box connections — the light goes dark. The LED fixture itself is rarely the first thing to fail.
The diagnostic path depends on whether you are dealing with a switched-style light (controlled by simple power interruption) or a network-style light (controlled by ProLogic or OmniLogic). The voltage checks are identical for both; the relay and controller logic differs.
Step-by-Step Troubleshooting
Step 1: Confirm the light is being called for
Before measuring any voltage, verify that the controller or switch is actually telling the light to turn on. If the light is on an automation schedule, confirm it is within an active time window. If using a simple switch or relay, verify the light relay is engaged. On ProLogic or OmniLogic, navigate to the light output and confirm the status shows "On." A light that is not being commanded on is not a broken light.
Step 2: Check for 120VAC on the transformer primary side
- Use a multimeter set to AC voltage and measure across the primary input terminals on the transformer.
- You should read 120VAC. If you read 0VAC, stop here — there is no power reaching the transformer.
- Common causes of absent primary voltage: tripped GFCI on the lighting circuit, a tripped breaker, or a light relay in the automation panel that is not energized.
- Reset the GFCI by pressing its test and reset buttons. If it trips again immediately, you have a ground fault — see the GFCI tripping article for that diagnosis path.
Step 3: Check for 14VAC on the transformer secondary side
- With 120VAC confirmed on the primary, measure across the secondary output terminals.
- You should read 14VAC. If you read significantly less — or 0VAC — the transformer has failed or is incorrectly wired.
- Important note for LTBUY11300 (300W) transformers: On this model, the secondary 14VAC output only activates when power is routed through the blue and white input wires. If the transformer was wired to different terminals during installation, the secondary may read 0VAC even though the primary is live. Verify wiring matches the transformer label before replacing the unit.
- If secondary voltage is confirmed missing despite correct wiring, replace the transformer.
Step 4: Inspect all junction box connections
- Open the junction box(es) between the transformer and the light(s). With a meter, verify 12–14VAC is present at the junction point — not just at the transformer secondary.
- Inspect all wire connections for corrosion, looseness, or broken conductors. Even a single high-resistance connection can drop voltage enough to prevent the light from operating.
- Tighten or replace any suspect connections. If connections look correct and voltage is still absent at the junction box, trace back the low-voltage wiring run for continuity.
Step 5: Isolate lights one at a time
- If you have multiple lights on the circuit and some work while others don't, disconnect the non-working lights one by one from the circuit.
- If an isolated light works when connected directly, the issue is likely voltage drop or transformer overloading when multiple lights are connected simultaneously.
- If a particular light doesn't work even when connected directly with confirmed 14VAC at its cord connector, the light itself has failed and should be replaced.
Safety Note
Always confirm primary-side power (120VAC) is off before opening junction boxes, touching transformer secondary terminals, or disconnecting light cords. Low-voltage secondary wiring is safe at 14VAC, but the transformer primary runs on full household current. Use a non-contact voltage tester to verify dead before touching any wiring.
Special Cases
All lights are dark but the transformer measures correctly
If you have confirmed 14VAC at the transformer secondary but no lights respond, the issue is likely in the low-voltage wiring between the transformer and the junction box — an open circuit or a severe voltage drop across a bad connection. Measure voltage at progressively further points in the circuit to find where it disappears.
One light works, adjacent one does not
When lights are wired in parallel from the same transformer and only one is dark, the dark light's cord or the connection at its cord entry point in the junction box is the most likely culprit. Try swapping a working light cord to that position to confirm.
Frequently Asked Questions
The light was working yesterday. What changed overnight?
The most common overnight change is a GFCI trip. Check the GFCI outlet or breaker on the lighting circuit first — it may have tripped due to a ground fault condition that developed after the light warmed up or cooled down. Water intrusion into the light's cord connection can cause intermittent GFCI trips after the system cools.
The transformer hums loudly but the light is dark. What does that mean?
A loud transformer hum with no light output usually indicates the secondary winding is loaded but not delivering voltage to the light — often a short circuit in the low-voltage wiring or a failed light drawing excessive current. Disconnect the light cord from the junction box and check if the hum reduces. If it does, the light or its cord has an internal fault.
My automation shows the light "On" but it is dark. Where do I look?
Confirm the light relay has actually engaged by measuring 120VAC on the transformer primary while the automation output is active. If the primary is dead, the relay is not closing — this could be a failed relay, a wiring issue at the relay, or an automation configuration problem where the output isn't assigned to the light relay.
Can a ColorLogic light simply burn out?
LED ColorLogic lights have very long service lives, but they can fail. Internal LED driver failures are the most common failure mode. If voltage is confirmed correct at the cord connector and the light still won't illuminate, try a known-good light in the same niche to confirm the fixture is the problem before condemning the wiring.
How do I know if my transformer is overloaded?
Divide the total wattage of all connected lights by the transformer's rated wattage. ColorLogic UCL lights typically draw around 65W each. A 300W transformer should not run more than four 65W lights. An overloaded transformer will often measure low secondary voltage under load (below 12VAC) and may run hot or hum excessively.