Weak brakes & battery box confusion.

[jonsstihl]

pull the emergency brake disconnect pin with the truck not connected to the trailer. check the voltage of the battery. This would load test your battery voltage should be above 11 when load is applied. If it drops suddenly that means the battery is no good. unless a bad connection is not applying a load to the battery....

 

[Snobdds]

The battery has nothing to do with how the brakes work, it's only there if a ground short (loose connection with the truck) happens, it will provide current to the brakes to stop the trailer. It's either a bad ground, or the trailer controller is not modulating the current to match the din setting requested.

If you have a power prob, supply 12v to the blue trailer break circuit and see if the tires spin. If no power prob, take a good battery with jumper testers, put ground on the ground lug and put the power to the trailer break circuit. If the breaks work you know its the controller. The controller may work, but it's not allocating current correctly.

 

[Sid Post]

Your 7pin connector has a ground wire in it. So your hitch/ball shouldnt be the ground path.

Not sure why but, the RAM had this when purchased new and with rust on the 1/2" collar, the trailer lost its ground. Went to a trailer shop and they said this was a common problem with Dodge pickups.

 

[beenthere]

Noticed trailer brakes are weak.
Battery box says “recharge” on battery, but battery is only 2 months old and electrical tester reads 12.4V
Brakes work, but don’t do a lot, even with brake controller fully cranked to 10.
The trailer is only a year old and brakes worked well when I first got it.

What should I start looking at? Wiring connections seem fine

Says "recharge", doesn't say buy a new battery. Have you tried just recharging the battery?

 

[RustyA]

If the trailer side of the 7 pin does not have a solid ground that it shares with the tow vehicle two things could happen ...
1. Breakaway battery would not properly recharge from 12v hot key on circuit.
2. Trailer brakes may not be able to provide amperage enough to firmly engage brakes.
Once again I would connect tow vehicle running and test for voltage at trailer battery. If below 14.2v I would clean and reground white wire on trailer side of 7 pin connector first.

 

[ddbackhoe]

I dont see a dedicated ground wire from trailer frame to truck so where are the lights and brakes grounded? Hate when they drive in a self tapper and call it good.

Just looked at the batter box picture again. Did you check the large white and blue wire connectors?

I’ve become a big fan of using heat shrink solder seal connectors for all my outdoor stuff.

Heat Shrink Solder Seal Terminals

Heat Shrink Solder Seal Terminals

www.wiringdepot.com

 

[Flogger]

Make sure you have the full 12+ volts on the brake wire from your tow vehicle. My bet is wiring. I have never purchased a trailer that I didn't rewire. The factory wiring on any utility trailer I ever owned was atrocious. Just bought a 25k# gooseneck trailer and when I checked the wiring it was done using techniques the brake manufacturer warned against over and over.

 

[topgun05]

Simple way to confirm a working ground system would be to connect the plug to truck but do NOT hitch to truck. If all the lights work properly then trailer ground to truck plug is good. That leaves the 2 wires for brakes on the trailer side. Diminished performance may be issue between the 2 axles meaning only 1 axle or 1 side of 1 axle working. you'll need to confirm @ each wheel

 

[bob1251]

little confused, power for brakes are supplied by the 7pin, connected to the truck, through the brake controller, the battery onboard is for emergency pin pull.

most trailer brakes are manual adjustment, have they been adjusted?

Did you check the connection on your plug to make sure there is no corrosion . One problem with electric brakes is if you don't have a good connection . Another thing you can check is make sure all your lights are working , another thing is to check the pin in your plug on the vehicle to see if you get power when pushing on the brake pedal . I have had problems before with the brake pedal switch getting out of adjustment and sometimes even braking . Good luck

 

[Hay Dude]

Says "recharge", doesn't say buy a new battery. Have you tried just recharging the battery?

I put a new battery in it upon purchase in 3/23. I didn’t trust the original battery that came with it.
Separate and bigger issue to me is the brakes not having the stopping power they originally had.