Abstract: A cargo strap monitoring system for real-time detection and reporting of cargo strap failure is provided. The cargo strap monitoring system may be a detector in the form of a cylinder that fits a winch slot. The cylinder provides a housing for circuitry operably linked to a pressure sensor. During normal operation a cargo strap is wrapped around and deployed from the spindle. The pressure sensor detects unsafe tension in the cargo strap. The circuitry includes a transceiver and a processor. Upon detection of an unsafe tension condition the transceiver transmits a warning to a remote monitor which may be located in a driver's truck cab. The remote monitor can be a mobile terminal such as a smart phone. The spindle with a slot and circuitry including the pressure sensor can be sold as a kit suitable for retrofitting to cargo strap winches.