I have a 2016 f150 with a 3.31 rear end. I usually have the gain set at 8 pulling around 6k pounds. When I step on the brake pedal the output graph only lights up 2 or 3 bars out of the 6 on there. It doesn’t matter if I barely step on it or step on the pedal hard it only lights up 2 or 3 bars. I have went in and changed my brake effort from low all the way up to high and it doesn’t make a difference. When I grab the brake controller and squeeze it all the bars in the graph light up. I was just wonder if this was normal or not?

 

Normal

 

Normal. When you use the brake pedal the computers are doing their wizardry. When you squeeze the levers it's just actuating a rheostat that modulates braking input.

If you ever have to get more aggressive with braking, you'll see the lights come on.

 

Once, only once, did I get the bars to light up almost all the way and that was slamming on the brakes slowing from 70 as traffic came to a stand still in front of me. Normally its just a couple at the most. The truck senses how much trailer braking is needed and applies as it sees fit, unlike aftermarket ones that will apply full braking when not needed.