Testing your Tow-Pro Liberty

To test your Tow-Pro Liberty brake controller, connect a 5 - 26W bulb or automotive test light (with a bulb in it, not LED type) between the ‘ground’ pin (no. 1) and ‘brake controller output’ pin (no. 2) of your trailer 7 pin plug.

The Tow-Pro remote head LED should illuminate BLUE (if the unit is calibrated) or flash BLUE/GREEN if calibrating is not yet complete.

With the test light attached for testing, we can either do this in one of two ways:

• Option 1 – While the Tow-Pro is still calibrating (BLUE/GREEN flashing occurring), you can press your foot on the brake pedal and slowly increase the dial from 0 through to 10 you will see the test light go from no brilliance to full brilliance. This is normal operation.
• Option 2 – Once the Tow-Pro is calibrated completely (solid BLUE LED illuminated), simply push in and hold the override button on the remote head and again slowly increase the dial from 0 through to 10 you will see the test light go from no brilliance to full brilliance. This is also normal operation.

These steps are handy to run-through once installation is completed and if you don’t have a trailer available to connect.

Once you do have a trailer available and connected, you have the ability to set the nominal setting. If you feel like you need more braking dial it up, if too much dial it down accordingly.

Why test with a 21W bulb?

Tow-Pro needs to be tested with a 5 – 26W bulb rather than a 55W bulb. The Tow-Pro will check for shorts on the trailer wiring and a cold 55W bulb has an initial “inrush” current as it first warms up that exceeds this trip point, and the Tow-Pro will see this as an intermittent wiring short. While a hot 55W bulb is not likely to reach this trip point, it is best to use a bulb size of approximately 5 -26 watts.