Sounds like you set it up properly according to the Prodigy Owners Manual
Guidelines from the manual for adjusting the power include:
1. Connect trailer to tow vehicle.
2. With engine running hold manual full left and set Power Knob to indicate 6.0
3. Drive tow vehicle and trailer on a dry level paved surface at 25 mph and fully apply manual knob.
If trailer brakes lock up:
Turn power down using power knob.
If braking was not sufficient:
Turn power up using power knob.
4. Repeat Step (3) until power has been set to a point just below wheel lock up or at a sufficient force as to achieve maximum braking power.
5. Using the brake pedal, make a few low speed stops to check the power setting. Trailer braking is initiated and terminated via the stoplight switch. When the brake pedal is released, trailer braking will cease.
If you donít feel the trailer is braking enough, you may want to re-adjust the power.
If youíre still not satisfied with the performance, call Tekonsha. I called them once and found their support staff to be very friendly and helpful.