16' Scamp grounding question

[cvanzan]

I'm having problems with the electric brakes on my'02 16' Scamp. They only work when I am using the anti-sway bar.

Does anyone know where and how the frame is bonded to the battery ground.
All of the electrics check out on the TV (4th Gen 4Runner with factory trailer package)

Thanks,
Charlie VZ

[Raspy]

It does sound like a grounding problem.

My Dad had a trailer that depended on the hitch for a ground. Bad idea. Especially with modern receiver hitches. I remember him putting a piece of steel wool over the ball before he hooked up. Then it worked fine.

On one of the trailers I rewired, I simply identified the ground coming from the tow vehicle plug and attached it with a lug to the trailer frame. You will have to test your system to see if you have a ground at the plug and where it goes on the trailer. Probably a simple 12v tester will do.

[Dave Fish]

I agree with Raspy. It's common to use the trailer frame as the 12v ground but you need a solid ground to the vehicle. Someone will correct me if I'm wrong but I'm pretty sure it will be the white wire coming from your plug. In my opinion a wired ground is best but using the frame is common.

If you have a bad ground, I would think you would also have issues with your lights. They could work but be dim.

I would check the grounds from the vehicle, between the battery andvget rest of the system and to the brakes. A circuit tester is your friend. One of those with a probe and a light will work for this.

[cvanzan]

Lights work fine. I suspect they are not using frame as ground return path.

Looking at other threads on the subject of grounding, it seems the best place to bond from is the converter. That will take care of 120vac and 12vdc.

Thanks all,
Chas

[Raspy]

Originally Posted by cvanzan

Lights work fine. I suspect they are not using frame as ground return path.

Looking at other threads on the subject of grounding, it seems the best place to bond from is the converter. That will take care of 120vac and 12vdc.

Thanks all,
Chas

I think the 120 volt side of the converter should be connected back to the shore tie ground that is bonded to the neutral. The 12v ground is a current carrying part of the 12 v circuit and not really a "ground", it's the negative side of that circuit. If they are tied together and you have an open ground on the 120 volt side, you could heat up the whole trailer and the tow vehicle. Careful.

[Raspy]

Since you have brakes on the trailer, I think you have a negative and a 12v hot from the tow for that circuit. You might have a fairly good ground to the trailer, but a bad negative to the brakes. This might explain why the brakes are poor but the lights work. Do some tracing and testing with a 12v probe style tester. When testing the trailer negative have someone apply the brakes.

[Borrego Dave]

Originally Posted by cvanzan

I'm having problems with the electric brakes on my'02 16' Scamp. They only work when I am using the anti-sway bar.
Does anyone know where and how the frame is bonded to the battery ground.
All of the electrics check out on the TV (4th Gen 4Runner with factory trailer package)
Thanks,
Charlie VZ

You don't say if this a new problem. You may want to check your tugs wiring to make sure the you've got the ground line running through the 7 pin and connected to the frame, not through the ball. Being you say they only work with the sway bar on, which is a second metal to metal connection from the tug for enough continuity. Your brakes are grounded to the frame. Think I would unscrew the brake wires from the frame, clean them up and see if that fixes it. Being your location, it may be as easy as some unseen corrosion .

[Byron Kinnaman]

One of the problems with electrical systems in trailers and people is that many people equate boat trailers with travel trailers. They're completely different animals. Boat trailers are submerged in water when load or unloading a boat. That along with using the frame as a negative conductor enhances corrosion, hence the myth that electrical problems are ground problems or a short.
Fiberglass trailers are different in that the negative power is run through a wire, except for the Safety Ground provided when plugged into shore power. The appearance of the frame ground is by the current from your ohm meter going through the grounding system in the converter.
As was indicated the electric brakes the the same through the converter ground and frame to work. There should never be any other current flowing in the frame. One and only one connection to the frame does not allow current to flow in the frame.

This is a topic that has been discussed many times on trailer forums and seem to be a difficult concept to grasp.

[Borrego Dave]

Originally Posted by Byron Kinnaman

One of the problems with electrical systems in trailers and people is that many people equate boat trailers with travel trailers. They're completely different animals. Boat trailers are submerged in water when load or unloading a boat. That along with using the frame as a negative conductor enhances corrosion, hence the myth that electrical problems are ground problems or a short.
Fiberglass trailers are different in that the negative power is run through a wire, except for the Safety Ground provided when plugged into shore power. The appearance of the frame ground is by the current from your ohm meter going through the grounding system in the converter.
As was indicated the electric brakes the the same through the converter ground and frame to work. There should never be any other current flowing in the frame. One and only one connection to the frame does not allow current to flow in the frame.
This is a topic that has been discussed many times on trailer forums and seem to be a difficult concept to grasp.

Byron, you've posted this same response before. Please explain how the grounding for brakes on cargo/enclosed trailer work without having a converter. Every one of the 50 or so I've worked on were frame grounded including the 2 boat trailers I had and they all worked fine.

[Wayne Collins]

One of the pins of the 7 pin connection is for a wired ground, That should have a heavy white wire connected to your TV battery's negative post, and routed all the way back to the 7 pin. Then the trailer has a mating wire connected to the battery negative. From there, another wire serves the ground circuit to all the lights, etc. as well as the frame. The brakes are grounded to the frame. You need to be sure there is no rust under those screws.
We had a 16 ft that one brake stopped working. It turned out to be a broken wire at the magnet inside the wheel. Had to take the wheel and drum off the replace the magnet,

[sokhapkin]

Originally Posted by Wayne Collins

One of the pins of the 7 pin connection is for a wired ground, That should have a heavy white wire connected to your TV battery's negative post, and routed all the way back to the 7 pin.

Cars and trucks use chassis for ground. Negative battery post is connected to the chassis somewhere near the battery, white wire from 7 pin is connected to chassis near the connector.

[Wayne Collins]

Originally Posted by sokhapkin

Cars and trucks use chassis for ground. Negative battery post is connected to the chassis somewhere near the battery, white wire from 7 pin is connected to chassis near the connector.

OK as long as you have clean connections,
It's the hitch ball and reciever that are not a good ground.

[sokhapkin]

Hitch ball is not supposed to be a ground connection. That's why trailer connector always has a ground wire. Even 4-pin connector.

To me the OP's problem looks like corroded trailer's ground wire to frame connection which is usually located somewhere near the axle.

[cvanzan]

I did check using ohm meter and found that the brake return was connecting only via the frame and not the ground wire in the plug. Following your advice I bonded battery ground to frame near the battery connection. I now have conductivity from the plug's ground wire to the brake connection. Should be good now. Thanks for all of the great advice, etc.

btw - I am now the owner of an Escape 21'

Charlie VZ