Lamp Ballast Fault Detected on Light Head

Common Symptoms

• COMMANDER controller display shows fault code 8 on the side panel
• One or more light heads fail to illuminate after warm-up period
• Tower raises and engine runs normally but one lamp stays dark
• Ballast box emits a faint clicking or buzzing sound as it attempts to re-strike the lamp
• Lamp flickers briefly at startup then goes out completely
• Yellow or red fault indicator illuminates on the operator panel alongside the code
• Other light heads on the same tower continue to operate normally

Probable Causes (Ranked by Likelihood)

• Moisture or water intrusion into the ballast enclosure causing internal short or corrosion on ballast board terminals Very Likely
• Ballast capacitor failed due to vibration during transport, causing the ballast to lose ignition voltage to the lamp Very Likely
• Lamp itself has failed or reached end of service life, causing the ballast to fault after repeated failed strike attempts Likely
• Loose or corroded wiring connection between ballast output and lamp socket, breaking the ignition circuit Likely
• Ballast igniter module failed internally, preventing the high-voltage strike pulse from reaching the lamp Possible
• Generator output voltage out of spec (below 108V AC or above 132V AC on a 120V circuit) stressing ballast input circuit Possible
• COMMANDER controller wiring harness fault causing a false ballast fault signal with no actual ballast failure Less Likely

Step-by-Step Diagnostic Procedure

1. Start with the tower lowered and the unit shut down. Open the ballast box on the affected light head and visually inspect for water staining, corrosion on terminals, or burned components. Any moisture or burn marks point directly to the failed ballast assembly.

2. Inspect the wiring harness from the ballast to the lamp socket. Tug each connector firmly to check for loose pins. Look for chafed insulation where the harness runs through the mast hinge point, since that spot sees the most flex during deployment.

3. Swap the lamp from the affected head with a known-good lamp from another head on the same tower. Power up and attempt to re-strike. If the replacement lamp fires in the same ballast, your original lamp has failed. If it still will not strike, the ballast is the problem.

4. With a multimeter set to AC volts, measure the generator output at the ballast input terminals while the unit is running. You should read 120V AC plus or minus 10 percent (108V to 132V). A reading outside that range means a generator or AVR problem is stressing the ballast, not the ballast itself.

5. If you have access to a clamp meter, check the line current draw on the working ballasts versus the faulted ballast circuit. A faulted ballast will show zero or near-zero current draw, while a good ballast striking a lamp will pull 4 to 6 amps on a standard 1000W metal halide head.

6. If moisture was found, dry the ballast box thoroughly with compressed air, treat terminals with electrical contact cleaner, and re-test before condemning the ballast. Some moisture-induced faults clear after drying.

7. If the fault persists after swapping the lamp and drying the box, the ballast assembly itself needs replacement. Ballast replacement on Allmand Night-Lite Pro II and Maxi-Lite II units is a direct bolt-in swap. This does not require reprogramming the COMMANDER controller.

8. If all physical checks pass and a new ballast still shows code 8, suspect the COMMANDER controller feedback wiring harness. At that point, contact your Allmand dealer or a qualified service technician to trace the signal circuit.

Frequently Asked Questions