When it is required to charge the vehicle battery, connect the positive connection to the battery positive post, and attach the charger negative connection to a body or engine ground. Do not connect the negative cable of the charger to the battery monitoring sensor. Connecting directly to the battery monitoring sensor bypasses the sensor, not allowing the sensor to detect the charge current. As a result the battery state of charge does not reflect the charging. Look for the body ground cable coming off the clamp of the battery monitoring sensor and connect in this location (typically on the shock tower sheet metal). The placement of the battery is such that the battery negative terminal is located under the sheet metal shroud making sheet metal ground the obvious choice for the charger.
Refer to: Battery (414-01 Battery, Mounting and Cables, Diagnosis and Testing).