Electric Brake Issues - Weak Brakes

Wear on one side indicates you already had an issue of non functioning brakes. There is no wear when they don't function.

I recommend starting with a DC clamp-on ammeter at each wheel. Full manual braking you should see 3 amps at each wheel. If they are all low you have a central connection issue. If one is low you have a problem with that one wheel.

When you installed the new brake, was the small shoe towards the front of the vehicle?

tsherv wrote:
I think I'm on to something: I tested the voltage of the blue wire coming from my brake controller while pushing the manual override. It measured 12 volts (which it should). When I tested the brake pin of the 7 pin connector, it only registered about 3 volts. I tested the blue wire right before it went into the 7 pin connector, and it measured 12 volts. I'm thinking maybe the 7 pin connector on my truck is bad?

I'm thinking you're correct.

tsherv wrote:
I think I'm on to something: I tested the voltage of the blue wire coming from my brake controller while pushing the manual override. It measured 12 volts (which it should). When I tested the brake pin of the 7 pin connector, it only registered about 3 volts. I tested the blue wire right before it went into the 7 pin connector, and it measured 12 volts. I'm thinking maybe the 7 pin connector on my truck is bad?

Sounds like you found it. Do check the other pins as well so you know that you have a good ground while checking with a voltmeter. Even with a bad connection, it is surprising that the reading is that low with no load.

Usually you should replace all brakes on an axle so they have the same effect. Yes, burnishing does take time and with only one side new, there will be quite a difference possibly pulling the trailer to one side. Don't believe those that discount the effect of burnishing, in recent years brake friction material has changed causing the poor performance when new.

opnspaces wrote:
I don't buy the burnishing. I've never burnished brakes and haven't noticed a difference in stopping power. Even if burnishing has an effect, I don't think it will have the effect you're looking for.

Mine didn't stop worth a **** until I burnished them. Was night and day after I did the burnishing procedure.

I do agree with running home runs for every wheel back to the tongue. Way easier to diagnose an electrical issue since you can isolate it to one wheel/circuit.

BTW...they are never wired serially. I think you are confusing it with "daisy chaining". The magnets are still in parallel.

My old truck has a Ampmeter for the brakes and is interesting to watch to see it change as I apply pedal pressure. Truck also has a hydraulic controller instead of the fancy electric ones with accelerometers.

Sounds like your onto something OP with the voltage drop at your connector. Corrosion most likely.

I had a tag axle with electric brakes on my last motorhome. I put an Ampmeter in the circuit so I could tell how much power was actually being applied to the magnets. The range of the meter was only 6 amps as I remember. You might want to try and find one. Ampmeters are wired in series with the brakes (the blue wire) so all power goes through it.

I don't buy the burnishing. I've never burnished brakes and haven't noticed a difference in stopping power. Even if burnishing has an effect, I don't think it will have the effect you're looking for.

You could have a wiring problem, or you could have an adjustment problem, or possibly both.

Here's what I would do in roughly this order.

Have a helper start the TV but leave it in park. Have them cycle the manual brake slide while you listen for a hum from each trailer wheel. If no hum from a wheel that brake is not working.

I have always hated adjusting drum brakes because the drums are never very round and you will hear light scraping long before they are adequately adjusted. I would adjust them to where you hear a decent drag. If you can turn the wheel by hand without really forcing it then they'll be okay. If you spin a wheel and let go and they spin more than 2-3 turns they are too loose.

Here's a few links to brake discussions.
Link 1

Link 2


You might have to run new heavier gauge wires to each brake. It will probably make the biggest difference out of all the changes. There was a post on here a few years ago by user Spike99 where they were using what they called star wiring. In effect it is parallel wiring to the wheels instead of the serial wiring that most manufacturers use. Here's a picture.

I think I'm on to something: I tested the voltage of the blue wire coming from my brake controller while pushing the manual override. It measured 12 volts (which it should). When I tested the brake pin of the 7 pin connector, it only registered about 3 volts. I tested the blue wire right before it went into the 7 pin connector, and it measured 12 volts. I'm thinking maybe the 7 pin connector on my truck is bad?

Are the on the correct sides?