Burnt negative to ground wire on 1992 Scamp 13'

[gordon2]

Originally Posted by bigb

Poor connections can do this. Loose or corroded connections as several have already noted. In the trade we have a saying "loose wires start fires". The fuse didn't blow because there wasn't an overload. The loose connection got hot and melted the insulation off the wire but since the load is not over the rating of the fuse it will never blow.

True but the heat is only generated at the point where the bad connection has high resistance. The wire will get hot some distance from the hot spot due to conduction, but not very far in most cases. My question is how far is the insulation melted from the point(s) where the wire(s) connected to the battery, frame, or other connection that might have been bad. The first pic shows a short length of wire so a bad connection at either end might be the sole problem. However the interior wiring photo concerns me since we dont know how far it is from the supposed bad connection.

Try putting a blow touch on the end of a ten gauge wire for a few minutes. A few inches from the end where the flame is some insulation will melt. A little further distance it will be too hot to hold. But go many feet from the end with the flame and it will be cool enough to hold.

In house wiring I have seen a bad connection at an outlet when a back stab was used, and under heavy load the insulation melted 2-3 inches from the outlet. How much further it might occur I would have to ask a fire department inspector. Obviously it sometimes is enough heat to start a house fire.

IMHO only, If OP can verify that a proper fuse was in use and did not blow, and the melted insulation is close to a bad connection (maybe to the frame), then a simpler repair might be appropriate (or it might not be).

[Raspy]

The term "ground" has a different meaning on a 120 volt system than on a 12 volt system.

"Ground" on a 120 volt system is not a current carrying wire, but a safety wire. Ground on a 12 system is really the negative wire. It completes the circuit. There is no safety "ground" on a 12 volt system.

I'm wondering if maybe your 120 volt common (white) wire is not continuous and you are running current to ground, or completing the 120 volt circuit through your 12 volt system. Your 120 and 12 volt systems may be bonded together at the ground point on the frame, for instance.

Or, if that is a #12 wire and you have a 30 amp charger, it might just be sending too much 12 volt current through that wire. The positive wire would not be affected if it was a #10 or larger, or if it had a 30 amp or larger fuse.

As suggested, it might be as simple as too much load from all of the appliances, lights, etc being on and being fed through too small of a wire. If you have an inverter, that wire is WAY too small and could be damaged in seconds if the trailer was unplugged.

With this problem, and melted wires in the wall, you need some good diagnosis of what is going on. Not too hard to do by an electrician.

[Ballman1]

Originally Posted by lisantica

What should I be looking for to have caused this negative battery wire to the ground on my 1992 Scamp 13'?

Background info:
Last time the Scamp was used was Thanksgiving hooked up to my house for electricity. Small electric heater was being used, it was raining on and off.

So what was outcome of the fried wiring since 2017 all Information is helpful?

BM1

[AC0GV]

Originally Posted by lisantica

What should I be looking for to have caused this negative battery wire to the ground on my 1992 Scamp 13'?

Did you have it fixed yet? What was found? TNX

[lisantica]

Originally Posted by AC0GV

Did you have it fixed yet? What was found? TNX

The work to replace the wires is scheduled for this Friday.
As the technician was looking over the job, the first thing he noticed were two wires that I had installed for a solar meter.

I temporarily installed the meter, but then took the meter out and had left the wires just bare, at the side of the sofa. I meant to get back to the job, but my father passed away and everything I was working on just didn't become important and I forgot all about those wires.

He's not sure if that's what caused it, and he'll know more on Friday when he does the job.

I'll report back.

In the photos:
Two bare wires I had forgotten about.
One of the items the electrician is going to install.

[AC0GV]

Originally Posted by Raz

2) I believe Scamp uses the frame as part of the brake circuit. If that's the case, in order for a break away circuit to work, the negative side of the battery requires connection to the frame. Check the brake wires.

Scamp will not install a break away switch, even if you beg.

[gordon2]

Originally Posted by AC0GV

Scamp will not install a break away switch, even if you beg.

But that does not preclude the possibility of there being one. And Raz only said it was a possibility.

Originally Posted by Raz

If the fuse was intact, the positive side did not conduct. As such, two possibilities come to mind....

2) I believe Scamp uses the frame as part of the brake circuit. If that's the case, in order for a break away circuit to work, the negative side of the battery requires connection to the frame...

And its a fact that Scamp does use the frame for the negative side of the brake circuit. Bad practice IMHO but if a break-away switch is added then a wire from battery to frame, such as the one shown burned, would make sense. It could be part of the problem, or part of the damage, or both.

BTW, My Scamp has a break-away switch and the switch and the brake circuit is wired independent of the frame to avoid connection problems.

[Raz]

My thinking was that a breakaway switch is wired between the positive battery terminal and the brake control wire (usually blue) from the tow and is unfused. A place to look. But the OP indicated the trailer doesn't have brakes.

I do have to wonder why Scamp won't install a breakaway switch. Not only is it a safety feature but they could make money doing it. Further, it's my understanding that some states require a breakaway switch be installed if the trailer is equipped with brakes no matter the trailer weight. Gotta wonder.

[lisantica]

Originally Posted by Raz

But the OP indicated the trailer doesn't have brakes.

True, no brakes. Floyd pointed out to me one time that I do have the mounting plates there for brakes. I never had them installed.
I had my Scamp weighed and it is 1,580 pounds fully packed.

The electrician starts the work today. I should have an update soon. I think it's just a one day job. We pulled back some wall covering from behind the sink and there were burnt wires there too as well as the front bunk where I first discovered it.

Surprisingly (maybe not to all), the running lights, brake lights etc. work. I was able to haul the Scamp to Arizona from California with lights.

[Raz]

Brake lights, running lights, and turn signals are all powered by your tow vehicle independent of the trailer battery.

[lisantica]

Originally Posted by Raz

Brake lights, running lights, and turn signals are all powered by your tow vehicle independent of the trailer battery.

True, I was just glad the wires that run the lights didn't get burnt.

[Vtec]

Speaking of an electrical problem. Middle of the night we wake up to smoke and fire above us as A/C was running in our 2010 Casita SD17. I pulled out that electrical outlet box next morning to find it melted. All the outlets in the whole camper were wired over the insulation. AC line wires overheated which is what I pictured. This was all factory wiring. Every outlet needed to be redone which I did myself. I brought it to Casita's attention and they more or less shrugged. I bet every camper that a certain person wired at the factory back in 2010 has the same faulty wiring.

[gordon2]

Originally Posted by Vtec

....All the outlets in the whole camper were wired over the insulation....

Wow, just wow... thats a whole new level of incompetence.

We see overheating and burning from back stab connections on outlets sometimes but the screw terminals are usually good. Of course you do have to remove the insulation at the end of the wire!

As fr the OP's burned up wiring.. now I wonder if the trailer was hit by lightening.

[k0wtz]

looks to me you got your hot wire to ground somewhere! hard to tell from my house.. LoL

bob

[steve dunham]

Anybody that has worked in the trades knows that is a picture of the classic cheap residential grade 29 cent receptacle .
In this case instead of splicing the wires out they used the receptacle as a splice ,increasing the chances of failure
The sad part is that whether you buy a $12k trailer or a $100,000 trailer you get the same sloppy electrical work
This is a great example of work performed by untrained , under paid workers
I’ve had to repair receptacles in my 2018 FG 21 and for the same reason - improperly terminated wires .

PS ; I’ve seen those same receptacles with 9 wires connected to them — 4 wires on the screws and 4 in the backwire holes + ground . A fire waiting to happen

[Vtec]

Originally Posted by steve dunham

Anybody that has worked in the trades knows that is a picture of the classic cheap residential grade 29 cent receptacle .
In this case instead of splicing the wires out they used the receptacle as a splice ,increasing the chances of failure

I was a bit surprised that the A/C did not have a dedicated line, or yes, pigtail wires to that one outlet rather than running current through it in line. To their credit Casita does use 12ga wire and the outlets were a step up from really cheap grade. I think if not for the insulation being tightened under the screws it would be a non issue. Every once in a while we would smell a plastic burning smell when A/C ran before it decided to flame and arc at 2-4am as I woke to my wife screaming. Real nightmare!

Why does all the scary stuff happen at night, like the propane gas sensor? That alarm really wrecks your sleep. I swear it must detect methane and propane, a gas is a gas, lol.

[steve dunham]

I always spliced out the wires and did not use the device for splicing
In the kitchen , laundry and other high power use areas , I used commercial grade receptacles instead of the el cheapos
I used metal boxes for ceiling lights instead of the blue plastic boxes that would deform and the fixture would fall down
We followed the code but used best trade practice

This also made it very hard to compete against non union contractors who cut every corner they could get away with .

[k0wtz]

steve my carpenter friend used some plastic boxes for the ceiling. I will just say it didn't work out. Sort of crazy when you see you ceiling fan flying around the room!

bob

Originally Posted by steve dunham

I always spliced out the wires and did not use the device for splicing
In the kitchen , laundry and other high power use areas , I used commercial grade receptacles instead of the el cheapos
I used metal boxes for ceiling lights instead of the blue plastic boxes that would deform and the fixture would fall down
We followed the code but used best trade practice

This also made it very hard to compete against non union contractors who cut every corner they could get away with .

[k0wtz]

Raspy my Scamp has a small black wire which is 12v hot running back into the trailer. I haven't tracked it down but I imagine it goes all the way back to the inverter.

Sort of strange but it must be legal. I have never turned on all my 12v appliances to see what happens? We use our portable lights and never use anything else off the 12v battery!

I don't have a water pump I see in the past where someone has almost burned up the old pump! We now use a hand pump much simplier in life!!

bob

Originally Posted by Raspy

The term "ground" has a different meaning on a 120 volt system than on a 12 volt system.

"Ground" on a 120 volt system is not a current carrying wire, but a safety wire. Ground on a 12 system is really the negative wire. It completes the circuit. There is no safety "ground" on a 12 volt system.

I'm wondering if maybe your 120 volt common (white) wire is not continuous and you are running current to ground, or completing the 120 volt circuit through your 12 volt system. Your 120 and 12 volt systems may be bonded together at the ground point on the frame, for instance.

Or, if that is a #12 wire and you have a 30 amp charger, it might just be sending too much 12 volt current through that wire. The positive wire would not be affected if it was a #10 or larger, or if it had a 30 amp or larger fuse.

As suggested, it might be as simple as too much load from all of the appliances, lights, etc being on and being fed through too small of a wire. If you have an inverter, that wire is WAY too small and could be damaged in seconds if the trailer was unplugged.

With this problem, and melted wires in the wall, you need some good diagnosis of what is going on. Not too hard to do by an electrician.

[Defenestrator]

Originally Posted by steve dunham

Anybody that has worked in the trades knows that is a picture of the classic cheap residential grade 29 cent receptacle .
In this case instead of splicing the wires out they used the receptacle as a splice ,increasing the chances of failure
The sad part is that whether you buy a $12k trailer or a $100,000 trailer you get the same sloppy electrical work
This is a great example of work performed by untrained , under paid workers
I’ve had to repair receptacles in my 2018 FG 21 and for the same reason - improperly terminated wires .

PS ; I’ve seen those same receptacles with 9 wires connected to them — 4 wires on the screws and 4 in the backwire holes + ground . A fire waiting to happen

Yep.. here's an example from my new Bigfoot. Not nearly as bad as insulation under the terminal screw, but still sloppy work and cheap parts. The top one I grabbed by the plastic insulator and the wire popped right off. Redit in and added a new one for my temperature sensor, but I'm seriously tempted to just redo the rest of them.