Fuse Under front Bunk on Scamp and shorting out

[lisantica]

On my 1992 Scamp, I have a 4-flat pin hook up.
Whenever I tow my Scamp, I notice that the 20 amp fuse at the battery box will blow out. So I replace the fuse, use the 12V system then repeat at next location.

I've taken a photo of the fuse under the front bunk, does this look correct? I can't seem to separate the parts.

I'm thinking about taking my 12V battery to an auto parts to have them test it, does that seem like a good idea? I don't have a tester.

Suggestions on what to do is appreciated.

The wire under the front bunk:

[sokhapkin]

Blown fuse usually means short circuit to the ground somewhere. Inspect your trailer wiring.

[gordon2]

Originally Posted by sokhapkin

Blown fuse usually means short circuit to the ground somewhere. Inspect your trailer wiring.

And stop replacing the fuse all the time until you find and fix the problem. Each time a fuse blows, it is almost surly protecting your wiring and / or electrical system from some defect. And every time it does, there is a chance that it won't. One failure is all you need to have a bad day.

EDIT: PS, you see that electrical tape starting to peel off. Sloppy work by someone. Perhaps there is somewhere on the hot side that also has failed insulation / electrical tape on a wire, and it is shorting to ground as you bounce down the road. I don't see how testing the battery will lead to finding the problem.

I also cant make out what is on top of the photo. This needs to be looked at in person.

[lisantica]

Thank you both for your replies. I just didn't know where to start.
It probably comes second nature to some of you, but I don't have any frame of reference of how/what to look for.

I have now looked more closely at the areas with electrical tape and the red side of the battery had a cable that had substandard tape on it, so I have purchased new electrical tape and taped up those shoddy spots.

I will know immediately if that fixed it because it just takes a short trip down the road and it shorts out.

[lisantica]

Okay, now I am at the spot where the trailer hooks into my van.
I have unwrapped the electrical tape and these 4 wires are snug in their yellow casings.
There are two wires that are not attached to anything.

Any suggestions? Or should I just re-wrap with new tape?

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[steve dunham]

EDIT: PS, you see that electrical tape starting to peel off. Sloppy work by someone. Perhaps there is somewhere on the hot side that also has failed [/QUOTE]

It may also be an indication of cheap electrical tape.
(HD special Chinese tape @ 69 cents a roll )
There is a reason most electricians prefer 3M #33+ or #88 electrical tape.
If a fuse blows then replace it ONE TIME and if it blows again STOP.

[lisantica]

Just bought this.

[EricAllyn]

you have a brownish wire that is not hooked in and a yellow wire cut off and up tight to the chain or hitch -- if you have a feed back -- are a break some place else, this may be the difficulty. If I remember correctly, your camper has no 12V system, so the only thing from the TV are the lights, the green and brown are usually turn lights, and brake lights, the other is the running lights. The fourth is the ground coming back. I would guess that the system some place in the lights, has a fault, or short, between a light and a ground, and that sometime during the trip, either a turn signal, or a brake light is making contact with the ground, and that blows the fuse. If I were to try to trouble shoot it, I would check the wires with a circuit tester, one side on the ground wire, and see if it registers at the hot side of any light, having first removed all the bulbs.
You will need a long piece of wire for this, and some patience. If you don't find anything, then try hooking up the TV, and repeat the process. If you still are unable to find it, then turn on one blinker, and check, then the other blinker and check, then have someone apply the brakes. This should pinpoint the system that is trouble, and you can then trace that wire down to where it is shorting out.

[EricAllyn]

Also looking closely at the picture, you have the green wire from the TV hooked to black, that likely is the black wire that is fused, and the brown wire from the TV is hooked to the green on the camper. Without a wiring diagram, it would be a guess, but I suspect that is part of the issue, you may be shorting when you have your blinker one, and tap the brakes.

Hard to know without a test meter.

[lisantica]

Originally Posted by EricAllyn

Also looking closely at the picture, you have the green wire from the TV hooked to black, that likely is the black wire that is fused, and the brown wire from the TV is hooked to the green on the camper. Without a wiring diagram, it would be a guess, but I suspect that is part of the issue, you may be shorting when you have your blinker one, and tap the brakes.

Hard to know without a test meter.

Thank you EricAllyn for the information. I do have a 12volt system in the trailer, it runs my Fantastic Fan and interior lights.

I think you may be getting close to the problem because the issues happen after hooking up to the tow vehicle. Otherwise, things inside the trailer work great.

Do you think I need to switch those wires around? I won't do anything until I hear from any of you on what to try.
I will buy a tester, I just need to know which one I could get on a Sunday. Maybe Walmart, AutoZone, Harbor Freight, all places open tomorrow.

[EricAllyn]

If your right and left turn signals are correct, then I wouldn't change the wires. If you have a friend who has a four wire hitch, have them come and hook up to the electrical portion -- no need to hook up the hitch, just the electrical. Put lights one, turn signals and brakes -- see if the fuse blows. If it doesn't -- then it is in the car portion, not the camper portion.

Also, when the fuse blows, do you lose the use of the fan? With a 4 wire connection, you should only have brake, turning, and running lights, nothing inside should be on power, since that is all you are hooked for. If you are getting power to do something else, it is likely where you are having trouble, and drawing power that blows the fuse. Do you have a 12 battery hooked up?

[EricAllyn]

Tester can be from anywhere, and can be a simple continuity tester, to a small volt/ohm meter. The volt ohm will tell resistance and current, can test for 12VDC and 120VAV -- it usually has a switch on the front that tells you what it is measuring. If you get one, read the manual that comes with it. You might also want to start making a diagram of what the electrical looks like as you work through this. Note wire color, voltage, what it goes to, and any connections.

[lisantica]

Originally Posted by EricAllyn

Also, when the fuse blows, do you lose the use of the fan? With a 4 wire connection, you should only have brake, turning, and running lights, nothing inside should be on power, since that is all you are hooked for. If you are getting power to do something else, it is likely where you are having trouble, and drawing power that blows the fuse. Do you have a 12 battery hooked up?

Yes, when the fuse blows I lose the use of the fan and the 12 volt lights that are inside the trailer, that is how I knew something was wrong the first time it happened.

I do have the 12 volt battery hooked up. The fuse that is blowing is the one that is inside the 12 volt battery box, a group 24 deep cycle battery. I took the battery to AutoZone yesterday and it tested good. It's only a year old battery.

[EricAllyn]

I would not worry about the battery, your problem is in the wires. At some point you are shorting the system out. That is what blows the fuse. I suspect that you may find that the TV hookup is the problem. I think you probably would do best to trace the wires from the 4 wire connecter through to the rest of the system. I the TV supposed to charge the battery while you drive? If that is the case you are not set up for it, and use of the brakes or turn signal is probably what is blowing the fuse, since it is also trying to charge the system. That over loads everything and blows the fuse. You need to hook up a regular tow plug to have something charge the battery and have a 12V system working the the camper. Also, you may have mixed systems, that is used the white wire (return in 120VAC systems but power in 12VDC systems) so that you wind up with a short.

Trace through the system and know where the wires go, and what they power. Then you will be able to identify what is shorting. I tend to think that it is not a tape or bad connection as much as it is a wrong connection.

[EricAllyn]

Lisa -- here is a scamp wiring diagram from the document section. Note that it calls for a fuse where you have one -- but you are wired to the tow vehicle differently.

http://www.fiberglassrv.com/forums/d...gram_Scamp.pdf

[stefman]

I think what everyone is missing is that you usually need 4 wires from your tow vehicle just to run the trailer indicator lights i.e. right signal, left signal, parking lights and a ground. lisaantica says there is a battery involved and interior lights being powered. That tells me you need at least 1 more wire between the tow vehicle and trailer for sure. If there is trailer brakes there is a 6th wire involved. The picture only shows 4 wires hooked up. Someone is cheating on how they are charging the battery and most likely back feeding a circuit which is causing a fuse to blow.

Best have this looked at by someone who knows at least a little about trailer wiring.

[lisantica]

This morning I hooked up my tow vehicle to the Scamp.

I tried to see if the fuse would blow after applying brakes, blinkers, blinkers with brakes. At this time the fuse did not blow. So I can say that if it does blow it will be when there is movement.

Next test is to drive the van for a short distance to see if the jostling makes the fuse blow.

Not sure if I fixed it by retaping all the bad tape with good 3M tape.

I do not have trailer brakes.

It would be nice if the tow vehicle would charge the deep cycle battery, so I will have a trailer wiring place make that change for me.

Thank you all for your help. I will report back additional findings and solutions.

[k0wtz]

Note the comment about the wrapped wire together that is a no on take that tape off and check for a short 2 wires touching

next you need to get yourself a multimeter they are free at H/F with a coupon.

Have someone help you this is the best and easyies way for someone not experienced it is hard but it doesn't take long to figure it out

just my 2c

bob

[lisantica]

Originally Posted by k0wtz

Note the comment about the wrapped wire together that is a no on take that tape off and check for a short 2 wires touching

next you need to get yourself a multimeter they are free at H/F with a coupon.

Have someone help you this is the best and easyies way for someone not experienced it is hard but it doesn't take long to figure it out

just my 2c

bob

There are some things I will tackle, but I've decided that electrical is not one of them, so I have contacted a mobile RV repair place to come and check it out. They will be here tomorrow at 2pm. I'll report back.

[k0wtz]

Lisa you have done the smart thing here is how I think about electricity. Learn the concept of the multimeter look at el. as flowing water if you have your 12v at one point usually before a fuse and nothing past the fuse you have a problem somewhere.


Maybe you can take a little class somewhere 12v is not hard you will not get shocked with it as with 110v! I am sure the rv repair guy will be generous to you!