Haulotte Star 10 Overload System Fault (Light Load)
Fault Codes & Symptoms
Overload alarm sounds and functions lock out with less than rated load. Related symptoms: - Inability to lift the platform. - Constant alarm sounding. - Machine functions disabled. The machine alarms and shuts down functions, saying it is overloaded when only one person is in the basket. We have to lower it from the ground controls.
Confirmed cause: Internal failure of the basket load sensor. A microscopic crack in the sensor body allowed moisture ingress over time, leading to corrosion and erratic resistance values. Repair performed: Replaced the basket load sensor. Calibrated the new sensor according to the manufacturer's procedure using certified weights. Verification: The machine was tested with a single operator and then with a full rated load. The overload system did not activate with the single operator but did activate correctly when the load exceeded the rated limit. All functions operated normally. Technician notes: - This failure mode is difficult to diagnose without the proper calibration tools to bypass the sensor. The sensor can fail intermittently or with a signal drift that is not immediately obvious. - Always perform a full load system calibration after replacing a sensor. Do not skip this step. - The fault was subtle; the sensor did not fail completely but provided an incorrect baseline reading, tricking the system into thinking the basket was already partially loaded when empty.