Can a brake controller get weaker over time?

I would suggest you pull a wheel and physically check the trailer brakes before buying a new controller.

It could be that some of your connections are corroded or there is a partial break in a wire.

X3. Almost certainly a trailer brake problem, not a controller problem. I think the suggestion for corrosion at connections is on the right track. Or even at your 7-way connection. But also make sure you don't have grease contamination. Did you recently service the bearings or pump grease in the zerks?

I would suspect every other part of the braking system before I suspected the controller.
Weak magnets, worn shoes, out of adjustment brakes, poor connections, etc.

Yes to above. Perhaps breaks just need to be adjusted from wear.

I had the same problem and it was the ground connection at the trailer. Follow the 7-way cord back to the trailer and see where it grounds to the frame, there are usually a bunch of grounds under the same bolt. Take the bolt out and clean everything up good and your brakes will be like new.

carringb wrote:
X3. Almost certainly a trailer brake problem, not a controller problem. I think the suggestion for corrosion at connections is on the right track. Or even at your 7-way connection. But also make sure you don't have grease contamination. Did you recently service the bearings or pump grease in the zerks?

X4

I have a flatbed trailer that had really poor brakes when new that failed in short order. When I checked the wiring, they had used Scotchlocks to connect the brake wires to the harness. When I soldered them instead, my controller went from showing 2-3 LED's to 6-7 when manually activated.

Fast forward a few years to when I added brakes to my small cargo trailer. It came with a heavy gauge wiring harness. Connected to the same controller it will max out the LED bar graph. I have to turn the gain way down for that trailer.

Wiring is everything when it comes to trailer brakes.

Thanks for all the replies .... I just replaced the 7way pigtail, so I'll check that ground, along with the wire connections. Also, replaced and relocated the 7-way on the truck side, so I'll recheck all that. Thanks again.

At 15 years old, I'd be checking the brake shoes & magnets as well.