The voltage on the 12V 5A DC motor drops to 4V when using the VNH5019 H-bridge - why?

Warm welcome,

I want to control a 12V 5A DC motor with no load (car wiper motor). For this, I am using a VNH5019 controller based on an H-bridge. The power supply on the 12V side is via a 12V battery ( Link to battery ). When the engine is connected directly to the battery, everything works, the engine revs. When connected via the controller, I only have less than 4V on the motor side instead of 12V. Why? I control the whole system with an Arduino for now. From the console I set the direction of rotation of the motor shaft and the current changes direction correctly.

And the colleague is feeding the pwm signal to the module? The pwm signal is used to regulate the speed.

Thank you krychu0505! The PWM signal was connected, but I did not have its initial value initialised in the code. Thanks again!