Finally Got My Trailer Brakes Working

[Dr_Snooz]

I've fought with them for nearly four years and I think I'm finally home. I replaced and re-wired the controller, replaced the complete axle and totally re-wired the trailer from tongue to tail. Yet I never could get them to work correctly. Finally, I was giving someone a jump start last weekend. We sat there for awhile waiting for the battery to charge, but nothing was happening. Finally, I tested the voltage output across the terminals on my battery and found it putting out 10.5 volts. Now I have a special battery with both side terminals and top posts. The power across the top posts where I had the jumper cables clipped was 10.5 volts, but the power across the side posts was 13.5. I moved the cables to the side posts, got them started and on their way. Then it occurred to me that I had my trailer brakes powered by the top posts. I did a quick re-wire to the side posts and they work now. 

I've never seen anything like that before and was wondering if this is a common problem or not.

[LTZ C20]

Wow. That's really wierd. Never seen that either.

[roundhouse]

Usually the controller only sends 3 or 4 volts to the trailer anyway

What kinda controller you using ?


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[Irish_Alley]

once when i worked at autozone we came across that problem. think it was the same way the side post had no power while the top post had all the power. well when he brought it in we tested it and its easier/faster to just test the top post. well it tested good and he looked a little puzzled at why his batter was dead. i cant remember if he took it home or what but we ended up testing the side post and found the problem. but that was the only time ive heard or saw this at autozone.

dont want to speculate on whats going on with your battery but each battery cell will hold 2.1 volts a 12 volt battery will be 12.6v. so a 6 cell battery minus one cell is 10.5 which makes sense but you still have all 6 cells on the side post.

[Dr_Snooz]

What kinda controller you using ?

I'm using a Dexter Predator DX. It was behaving very strangely. Sometimes it would send 1 amp to the brakes. Sometimes 0.5. Mostly nothing at all. Sometimes I could operate the brakes manually. Other times not. One time it even buzzed at me, which scared me.

I never would have figured it out had I not given those people a jump. I would have eventually given up on having trailer brakes, and with the hills around here, that wouldn't be good.