Trailer Brakes

[MB43]

The brakes on my trailer have me baffled...

Without the trailer's plug connected to the truck, the light on the brake controller is bright and I've got voltage on the brake pin on the connector on the truck. When I connect the trailer's plug to the truck, the light on the brake controller is dim and there is voltage on the same pin, but the trailer's brakes don't engage.

The line from the plug on the trailer goes to a battery for the breakaway kit, and then on to the brakes themselves. I haven't changed the battery since I got the trailer, which was in 2001.

Is it possible the battery is no good? What would happen if it was no good?

I thought about it being a bad ground, but the lights on the trailer work fine... brake lights, tail lights, directionals, etc. I would think if there was a bad ground then the lights wouldn't work either...

Any other ideas about what could be going on?

 

[Swinger71]

You may have to increase the level and/or the gain on the brake controler in the cab

 

[krabysniper]

Yes, I would replace the battery. Sounds to me like the battery is toast. They charge from the vehicle and if you don't pull the battery when you store them for any length of time and put them on a trickle charger or charge them up every now and again they go bad and cause troubles. In my expierence anyway.

 

[MB43]

Well, after pulling the wheels apart and checking the voltages at all 4 corners, my buddy stopped by with his truck. We hooked his up and the brakes came on immediately. I guess my brake controller is toast. :-(

BTW, I checked the voltage coming out the battery and found that it had voltage, so that seems to be ok. For now, at least.