Abstract: The sudden unrolling of an motor driven overhead door is a hazardous occurrence. The invention provides a method of detection and warning of a damaged counterbalance mechanism or other defect in the door lifting assembly. The amperage readings of the drive motor are observed to increase between 5% and 30%, above that of normal operation when the function of the counterbalance assembly or similar drive assembly component is compromised. The method is reduced to practice as a number of alternative electronic circuits which are placed between the line power source and the drive motor. The circuit senses the motor amperage draw and compares the reading with a preset threshold value. Upon the sensed value exceeding the threshold value, a warning is broadcast. This method alerts one of undue strain on a damaged lifting assembly prior to its catastrophic failure.