Lamp Received Power But Failed to Strike

Common Symptoms

• COMMANDER controller display shows fault code 9 on the side panel
• One or more light heads remain dark even though the generator is running and other heads are lit
• Yellow or red fault indicator illuminates on the operator panel after lamps are commanded on
• Tower raises and generator runs normally but no light output from the affected head
• You can hear the ballast attempting to fire but the lamp never brightens
• The COMMANDER controller may cycle the lamp start sequence two or three times before locking out
• Runtime hours on the affected lamp fixture are high, suggesting bulb end-of-life

Probable Causes (Ranked by Likelihood)

• Metal halide or quartz bulb is at end-of-life and no longer strikes reliably Very Likely
• Lamp socket contacts are corroded or have high resistance preventing igniter voltage from reaching the bulb Very Likely
• Bulb is physically cracked, blackened at the base, or has a broken arc tube Likely
• Ballast or igniter module has failed and is not producing sufficient strike voltage Likely
• Wiring harness between the COMMANDER controller and the lamp head has a broken wire or loose connector Possible
• Lamp was recently replaced but the wrong wattage or base type was installed Possible
• Ballast capacitor has degraded, reducing strike energy below the lamp's minimum ignition threshold Less Likely

Step-by-Step Diagnostic Procedure

1. Check the runtime log on the COMMANDER controller display. Metal halide lamps on Allmand towers are rated roughly 2,000 to 6,000 hours depending on bulb type. If hours are near or past that range, start with a bulb replacement before doing any electrical testing.

2. Visually inspect the lamp bulb through the fixture glass. Look for blackening around the base or arc tube, white powder deposits inside the outer envelope, or any visible crack. Any of these means the bulb is dead. Replace it and clear the fault.

3. With the tower lowered and generator OFF, open the lamp head housing and inspect the socket. Use a flashlight to look for green corrosion, melted plastic, or carbon tracking on the socket contacts. Clean light corrosion with electrical contact cleaner and a small brass brush. Heavy corrosion or melting means you need a replacement socket assembly.

4. Check the lamp base seating. Pull the bulb straight out and reseat it firmly. A loose bulb in the socket creates intermittent contact that looks exactly like a no-strike fault. Make sure the base pins are fully engaged.

5. Inspect the wiring from the ballast box to the lamp head connector. Tug gently on each wire at the connector body to find any broken or pulled-back terminal. Measure continuity with a multimeter from the ballast output terminals to the socket contacts. You should read close to 0 ohms on each conductor. Any reading above 2 ohms indicates a wiring fault.

6. If wiring and socket check out, measure the ballast output voltage with the generator running and the lamp commanded on. On a standard 1,000-watt metal halide circuit, the igniter produces a high-voltage pulse (up to 4,000 volts open-circuit). Use only a high-voltage-rated meter on this test, or skip it and have a service tech do it. A ballast that produces no output voltage at all needs replacement.

7. Swap in a known-good bulb of the correct wattage and base type. Command the lights on from the COMMANDER controller. If the replacement lamp strikes cleanly, the original bulb was the problem. If the new bulb also fails to strike, the fault is in the ballast or igniter circuit and you need a ballast replacement or shop-level diagnosis.

8. After correcting the fault, clear the code on the COMMANDER controller display and run the unit through a full light-on cycle to confirm the fault does not return.

Common Fixes by Vehicle

What techs usually find when diagnosing ALLMAND-9 on specific platforms:

Frequently Asked Questions