Electric brake problems

[hrcarver]

I have a 10 yr old deckover trailer that has electric brakes. Only one tire acts like it has any brakes. I have adjusted all 4 brakes and it didn't make much difference. The one that works properly is the first that the power gets to, the rest are wired in line from there. The other three will all slide on grass, but not the road (empty trailer and braked turned all the way up). Could the voltage not being getting to the the others as strong for whatever reason? Any other ideas? I figured they just needed adjusting, but that was not it.

 

[Diamondpilot]

Could be bad connections between them. I would re wire it from the first brake on. If that is not it its time to check the shoes and magnets.

Chris

 

[hrcarver]

Three questions...

Do they "trip" when they wear out?

I was under the assumption if the brakes tighten up properly when adjusting, the brakes are still good. Right or wrong?

What should I look for as a sign of being worn out (shoes/magnets)?

 

[oliver1555]

Each magnet should draw 2.5 - 3 amps if wiring is of adequate size. Just another thing to consider checking.

 

[Diamondpilot]

Shoes will get grease on them if the seals are bad. Its then time to replace. Only way to know is open it up.

Chris

 

[MillWeld]

I The one that works properly is the first that the power gets to, the rest are wired in line from there.

Someone correct me if I'm wrong but it the wiring order doesn't matter because they are wired in parallel; they all "see" the same voltage.
Bob

 

[Lil_FarmerJim]

My suggestion is check the grounding on each wheel. I've had 2 trailers that had a similar problem and it was a simple ground wire that had rusted. The electrical potential was reduced and it caused the brakes to not work as well and on one not at all.

The ground wire should be connected to the trailer frame right at the brake for each wheel.

 

[Soundguy]

if it is using taps, I'd rewire. also, might pay to add something mor ethan the (possibly) 14awg plain flat ribbon trailer wire under there they may be using.

or at least double it up..

soundguy

 

[Soundguy]

Someone correct me if I'm wrong but it the wiring order doesn't matter because they are wired in parallel; they all "see" the same voltage.
Bob

yes but.. if each parallel ckt adds another crimp conector.. it can start loosing good connection fast.

insufficient grounding is always an issue I see too.

soundguy

 

[hrcarver]

if it is using taps, I'd rewire. also, might pay to add something mor ethan the (possibly) 14awg plain flat ribbon trailer wire under there they may be using.

or at least double it up..

soundguy

Umm, what's a tap?

 

[jeffsw6]

if it is using taps, I'd rewire. also, might pay to add something mor ethan the (possibly) 14awg plain flat ribbon trailer wire under there they may be using.

There is really no need to use a heavier gauge wire. If I was going to rewire my trailer I would use cable with a different type of insulation though.

I don't know what type of automotive cable is correct to use. SOOW / SEOOW cable, though, is fairly common for portable commercial/industrial uses. These types of cable are submersible, oil-proof, and have a tough outer jacket. The E variant has nylon inside for strength and heavier outer jacket. Both remain flexible to pretty low temperatures. That is what I would use, but as I said, I am no expert in automotive electrical, so I imagine there is a similar specialized type of cable for use on vehicles.

 

[Soundguy]

Umm, what's a tap?

Wire Tap-In Squeeze Connectors (10-Pack) - RadioShack.com

or any similar style of 't' style or 'y' style 1 in, 2 out, or 1 continous/1 extra out , 'crimp' style connector.

I see them ALL the time under trailers. my big tex had them and they were the prime cause of one sod eof my brakes not working.. I stripped them all out and went with a solder connector, heat shrink, grommets for wires, and liquid connector sealer.

soundguy

 

[hrcarver]

OK, I do have those I didn't know what they were called.

 

[Soundguy]

there are even 'cehaper' ones that don't work as well either..

i'm not fond of these for under-trailer work...

 

[oliver1555]

Brakes should never be grounded to any point on the trailer if you expect them to work correctly. You should always connect the ground wire from the magnet to the ground wire in the 6 or 7 wire cable (depending on what you have) and through the plug to the tow vehicle and ground it there. All connections should be soldered and made water tight with adhesive shrink tube or covered with liquid electrical tape. Moisture is your enemy and needs to be sealed out. Any time you depend on a connection to the trailer's frame to carry the ground, you have the potential (likelihood) that corrosion will reduce the ability to carry the required amperage at that location. Plus, if you are grounded to the axle, you are relying on your suspension's moving parts to provide the ground. The magnet needs to be supplied not only the proper voltage, but also the proper amperage. Most, but not all factory wiring jobs are substandard. In many cases, it is easiest and best to get a 6 or 7 wire trailer cable and start over. Trailer electrical problems usually show up when you are least able to fix them, like at night. I'd much rather rewire in my shop than on the road in the rain or snow.

 

[MillWeld]

Like oliver..., I'm more comfortable not relying on a steel/copper connection for a ground due to rust. When I rewired my trailer I ran a 12 gauge copper wire loop with all the other wires around the trailer and spliced into it where I needed and silver soldered the connection and covered with elec tape. This is in effect two 12 gauge wires for ground. For non-grounding connections sometimes I will use wire nuts filled with silicone rubber.
Bob

 

[RobertN]

I have always heard of them as "Scotch-Locks".

Bad, bad invention...!!! They are, cheap, quick and easy. But, they fail quick and easy too. And often leave the wires damaged.

Wire Tap-In Squeeze Connectors (10-Pack) - RadioShack.com

or any similar style of 't' style or 'y' style 1 in, 2 out, or 1 continous/1 extra out , 'crimp' style connector.

 

[Soundguy]

down here we call wire nuts scotch locks..

 

[lostcause]

down here we call wire nuts scotch locks..

you guys have a whole different vocabulary down there on the other side of that line. i worked in thomasville, ga one year, and there were a few of us "yankees" down there at the time. we had a running list of the words you used along with the translation we could understand.

seriously though, when someone says scotchlocks up here we all think of the no-strip taps like posted in the pics, but it looks like according to 3m there are a bunch of connectors that fall under the scotchlock trade name.

 

[Soundguy]

yep.. almost one of those 'kleenex' / 'facial tissue' issues.

that and the rosetta stone translator from south to north/north to south..