Unknown power wires

[dewayned]

I have just purchased a 2000 r-vision 8301 trail lite Travel trailer. There are some wires under the sink that I could not figure out what they were for. After replacing the battery, I figured out they are for a short stop that has been removed. The strange thing is that there are three red number eight wires. If I connect two of them, I get power to the 12 V lighting. I cannot figure out what the third wire goes to. Everything seems to be working.

[Boon_Docker]

On the line side, which would be a direct route to the battery.

[dewayned]

Looking further this evening, I found a 4-square junction box where the trailer lights wiring and the breakaway switch wiring terminate. And as I suspected, I found my mysterious red 8 ga wire in the box as well, wired in series to the breakaway switch. So I have little doubt that the auto reset circuit breaker was previously installed at the location of the three red wires.

I do question why it was removed. Aparently it was like this when the previous owner took possession. I notice that the breakaway cable is frayed and broken and in need of replacement. I don’t know if this is related.

Question: Would the breakaway branch circuit conductor go on the line or load side of the auto reset circuit breaker? I would suspect it should go on the line side like a fire pump.

Thank you all for you contribution to this thread. Your help and patience is greatly appreciated.

[BarneyS]

Look on the back side of the 1st frame crossmember that spans the front of the trailer right behind the A frame. This is a common place to find the "shortstop".
Barney

[drsteve]

dewayned wrote:


Question: Would the positive power for the emergency trailer brakes (not sure what to call it) be powered directly from the battery? Or would it come from the fuse box in the power center?

Right off the battery.

[dewayned]

SoundGuy wrote:

dewayned wrote:
A short stop is an automatic reset circuit breaker designed to protect the battery and the power supply in case of a direct short.

...hey whatever floats your boat! :W On a trailer it will be located not far from the battery which is usually mounted on the tongue.

If my terminology is wrong, I apologize. I had never heard of one until this weekend. And I am a Master Electrician of 15 years and in the business for nearly 40. The person using the term, I think on etrailer.com, used it like everyone should know the term. So I was just repeating what I heard.

I have read that it is usually on the tongue. But I didn't find one there, the there were two screw holes in the wood where I found these wires that seemed to match an auto reset circuit breaker. Maybe I overlooked it and this was supposed to be a disconnect switch. I will have to investigate some more.

Question: Would the positive power for the emergency trailer brakes (not sure what to call it) be powered directly from the battery? Or would it come from the fuse box in the power center?

[jerryjay11]

https://images-na.ssl-images-amazon.com/images/I/31wm-%2BQdJfL.jpg

Never heard it called that before either, but here it is.

[Boon_Docker]

SoundGuy wrote:

dewayned wrote:
A short stop is an automatic reset circuit breaker designed to protect the battery and the power supply in case of a direct short.

Referring to an auto reset circuit breaker as a "short stop" would be a new one on me, and to pretty well everyone else I suspect but hey whatever floats your boat! :W On a trailer it will be located not far from the battery which is usually mounted on the tongue.

Shortstop

[SoundGuy]

dewayned wrote:
A short stop is an automatic reset circuit breaker designed to protect the battery and the power supply in case of a direct short.

Referring to an auto reset circuit breaker as a "short stop" would be a new one on me, and to pretty well everyone else I suspect but hey whatever floats your boat! :W On a trailer it will be located not far from the battery which is usually mounted on the tongue.

[dewayned]

A short stop is an automatic reset circuit breaker designed to protect the battery and the power supply in case of a direct short. It’s similar to the Utility company’s cut out fuses in the power lines or inside the pad mount transformers serving our homes. The circuit breakers in our homes protect everything inside the home. The utility company fuses protect the wiring coming into our home. Likewise our breakers (120v) and fuses (12v) protect our trailer devices (plugs, lights, a/c etc... and the short stop protects the wiring to the power supply from the battery.

[SoundGuy]

dewayned wrote:
I don’t know yet if electric brakes are powered by the trailer power or the truck power.

Trailer brakes receive power from the brake controller mounted in the tow vehicle. The exception to this is in the unlikely event the trailer breaks away from the TV, in which case the lanyard for the trailer's brake system breakaway switch will pull and full power from the trailer battery will be applied to the trailer's brakes. None of this wiring inside the trailer but on the tongue.

And I too have to ask - what the heck is a "short stop"? :h

[dewayned]

I ohmed the wires to confirm that one goes directly to the positive in the power supply 12v section. The other definitely goes directly to the battery positive. I have not found where the other wire goes. There are no more wires in the power supply. And I have had it opened and taken apart. I had to lubricate the power supply fan as it was not working properly and was noisy. Another thought is maybe it has something to do with electric brakes? I don’t know yet if electric brakes are powered by the trailer power or the truck power. I am investigating that now.

[opnspaces]

Hi and welcome to the forum. What is a short stop? Are you referring to a surge protector? Does your trailer have a converter charger installed or could that be what the wires were for? Maybe the third wire goes back to positive on the battery to change it when on shore power.