Scamp brake and running light trouble

[Dennis J. Kane]

Hi Folks,
I have a '92 Scamp 13. I have been using this camper for 4 or 5 year.My lights have always given me trouble. Tonight I managed to get the brake lights to come on, with my foot on the break pedal and my head lights off. When I turn the head lights on ...No lights, no signals, nothing. Turn my head lights off, flashers and break lights work again. No running lights at all.

I have a flat 4 Toyota factory harness to a roung 6 pin adapted harness on the camper. The white ground is tap screwed right into the metal frame. I do not have elec brakes, those wires are dead. When I hook into a diff trailer, no issues. It is a problem with the camper. The crazy part is I usual say "f" it and pull it in the day time with no running light and bingo... they come on. Do I replace the harness? Can I spice the flat 4 into the round 6 pin and cap off the brake wires??? How do I know what color wires do what?
HELP.
PS Mod. question. Ever rip out the "kitchen" to make a bed. Head towards kids bunks and feet towards wife's feet. Kind of a L shape Master bed.???
Dennis

[Byron Kinnaman]

Hi Folks,
I have a '92 Scamp 13. I have been using this camper for 4 or 5 year.My lights have always given me trouble. Tonight I managed to get the brake lights to come on, with my foot on the break pedal and my head lights off. When I turn the head lights on ...No lights, no signals, nothing. Turn my head lights off, flashers and break lights work again. No running lights at all.

I have a flat 4 Toyota factory harness to a roung 6 pin adapted harness on the camper. The white ground is tap screwed right into the metal frame. I do not have elec brakes, those wires are dead. When I hook into a diff trailer, no issues. It is a problem with the camper. The crazy part is I usual say "f" it and pull it in the day time with no running light and bingo... they come on. Do I replace the harness? Can I spice the flat 4 into the round 6 pin and cap off the brake wires??? How do I know what color wires do what?
HELP.
PS Mod. question. Ever rip out the "kitchen" to make a bed. Head towards kids bunks and feet towards wife's feet. Kind of a L shape Master bed.???
Dennis

If you don't have a converter the negative, (some call ground) is NOT connected to the frame. Even then no current should flow through the frame.

If the trailer is wired correctly a standard 4 pin to 6 adaptor should work. I would try that first. If that doesn't work get a copy of the wiring schematic from the Scamp web site. Start checking the wiring from the connector according to that schematic. It's pretty easy to follow. A Mulitmeter would be a big help here.

[Darwin Maring]

If everything works OK on a different trailer then you know where the problem resides.

Check your grounds on the egg. The white wire from the plug to the frame of the egg and the grounds from the lights to the frame and make sure the connections are not rusty where they attach to the frame. (Grounds seam to be the biggest problem with trailer lights)

Inspect the plug on the trailer to insure it is not damaged and clean both the plug and receptacle of both vehicles. Make sure it plugs into the receptacle OK.

Crapshack sells a $15USD kit for cleaning and preserving the connections. It has 2 very small aerosol sprays (The size of a lipstick), it seams quite expensive for such little material however the magazines have raved about how great it is.

If after cleaning, things don’t improve, then you need to completely check the wiring from end to end.

Sometimes it is easier to just install new trailer wire / plug than to check the old stuff especially if you do not have the equipment and/or expertise to do the test. If you do that, you might want to consider retrofitting to LED lights. They are sealed, use very little current and should give you many years of worry free service.

[Byron Kinnaman]

If everything works OK on a different trailer then you know where the problem resides.

Check your grounds on the egg. The white wire from the plug to the frame of the egg and the grounds from the lights to the frame and make sure the connections are not rusty where they attach to the frame. (Grounds seam to be the biggest problem with trailer lights)

Darwin,

I'm curious how the wires from the lights get to the frame. If you have wires going to the frame at each light it's probably somebody's modification. My 2006 13' from the factory has one wire attached to the frame and that wire is the "safety ground" from the 120 AC system. Since the tail lights and running lights are wiring have to come through the shell to the inside of the trailer to drill a bunch of holes in the floor to connect to the frame. It's a lot easier and less expensive to just run a wire around the inside of the trailer for the negative connection.

[jim munson]

The wires inside the trailer were corroded. I abandoned all the wires and fixtures and replaced them with a boat trailer harness that I stapled to the underside of the camper.
Now they can be seen and not get corroded in a damp interior enviroment.

[Byron Kinnaman]

The wires inside the trailer were corroded. I abandoned all the wires and fixtures and replaced them with a boat trailer harness that I stapled to the underside of the camper.
Now they can be seen and not get corroded in a [b]damp interior enviroment.

HUH?

[Pete Dumbleton]

Some eggs tend to be more damp under the benches than others, particularly where the water tank is (condensation) and where the porta-potti is (evaporation of flush water), esp because there is typically poor ventilation. However, I would be inclined to keep the wiring inside (and deal with the moisture instead).

Some folks have even reported corrosion of the metal clips used to hold the LP lines in place.

BTW, I have often heard and read of automotive systems described as 'negative ground' and 'posititive ground', plus DC electronic systems having 'chassis ground', so I would presume it to be a good term even when nothing may be connected to an 'earth ground'. YMMV

My experiences and readings of automotive and trailer lighting systems leads me to believe there are three causes for the majority of problems. In order, they are:

1. Bad grounds

2. Bad grounds

3. Bad grounds

[Byron Kinnaman]

Some eggs tend to be more damp under the benches than others, particularly where the water tank is (condensation) and where the porta-potti is (evaporation of flush water), esp because there is typically poor ventilation. However, I would be inclined to keep the wiring inside (and deal with the moisture instead).

Some folks have even reported corrosion of the metal clips used to hold the LP lines in place.

BTW, I have often heard and read of automotive systems described as 'negative ground' and 'posititive ground', plus DC electronic systems having 'chassis ground', so I would presume it to be a good term even when nothing may be connected to an 'earth ground'. YMMV

My experiences and readings of automotive and trailer lighting systems leads me to believe there are three causes for the majority of problems. In order, they are:

1. Bad grounds

2. Bad grounds

3. Bad grounds

Negative DC power is connected to the frame in automotive, utility trailers, and boat trailers. Mainly because the light fixtures are attached the frame (running and stop lights). I haven't seen any fiberglass trailers with light fixtures attached to the frame. Maybe I'm missing something.

[pjanits]

And there is always the ever troublesome bad grounds. Hard to find but easy to fix once found.

[Pete Dumbleton]

Well, if the light fixtures have a white wire, and the tow vehicle has a white wire and the converter has a white wire, and the converter's white wire is connected to the frame and the frame is connected to the tow vehicle by white wire and hitch, then I believe we have negative ground wiring in the tow vehicle and trailer, even if the light fixtures are not mounted directly to the frame. But, guess it doesn't really matter as long as we don't start connecting the positive wires to the white wires...

[jim munson]

Bryan
The damp interior enviroment I was refering to is condensation on the inner wall of the fiberglass. All my marker lights and splices had a white oxidation coating. Putting the wires under the floor stopped that crap. Routing new circuits is easier from under too.

[Byron Kinnaman]

Well, if the light fixtures have a white wire, and the tow vehicle has a white wire and the converter has a white wire, and the converter's white wire is connected to the frame and the frame is connected to the tow vehicle by white wire and hitch, then I believe we have negative ground wiring in the tow vehicle and trailer, even if the light fixtures are not mounted directly to the frame. But, guess it doesn't really matter as long as we don't start connecting the positive wires to the white wires...

You missed one. You gotta have a white wire from the fixtures, each and every one them, to the frame.

And nobody said anything about negative ground or it's counter part positive ground.

Now go looke at the Scamp wiring schamatic and find ground. I believe the only reference to ground you'll see is associated with the 120 AC power system. The negative side of the DC power is only refered to as a white wire. I don't find any indication on the schematic where the white wire is connected to the trailer frame.

Explaination of how the trailer frame is connected to the negative DC system;

a. Where there is a piece of electrical equipment that has a metal chasis, i.e. the converter the AC ground must be connected to the metal chasis of the converter. This is a safety thing.

b. If you have AC electrical outlets the AC ground then must be connected to the trailer frame. Safety again. (Safety issues are required by UL and CSA)

b. Electronic power supplies (Converter) usually will connect the negative DC power to the metal case, again a saftey thing.

c. Since the metal case of the Converter (power supply) is connected to both the negative power system and the frame of the trailer via the AC ground, it appears that the trailer frame is the negative DC system power connection. Since the light fixtures are attached to the plastic trailer body there has to be some way for the negative and positive DC power to get to the lights. That has to wire.

It can be very confussing and I can see that is. That confussion is why I don't the use ground associated with fiberglass trailers, everybody want to associate ground with the trailer frame when what they're talking about is the negative side of the DC power.

[Darwin Maring]

Throughout the years I have experienced every sort of tail light problem you can think of on vehicles and trailers.

When you have a single wire going from light fixture to light fixture (In Series) and attaching in one place to the frame and/or the plug all it has to do is go bad in one spot and nothing else works, So now days, on all my trailers, camping and utility, I make sure that the ground wire on each light is fastened to the frame. I use the wire that was installed in and underneath the camper and simply splice a run to the frame and then allow the original wire to continue to the next light (This is parallel Wiring). Yes, I have a frame ground for each light which means that I have multiple grounds. I also have done this for the electric brakes and that has overcome previous braking problems.

My white wire (Negative) on the truck goes to the frame of the truck and the white wire on the trailer plug goes to the frame of the trailer and I have a ground strap bolted to the tong of the trailer hitch with a big battery alligator clip that I attach to the receiver of the truck, yes, another ground. You can’t rely on the trailer Ball / hitch to provide the ground as many people unknowingly do.

I have retrofitted all my trailers with LEDs on the back and side markers and with all this work, I haven’t had problems in years.

The negative path for all lighting on trucks and autos travels through the frame / body of the vehicle. The battery of the vehicle has the negative side bolted directly to the metal of the vehicle either the frame or engine. The positive side of the battery usually goes directly to the alternator.

When you look at the new vehicles today you will see bolted ground straps all over the place. This is due to the plethora of plastics used and for the manufactures to insure they have quality grounds to every part of the vehicle.

[Brian B-P]

Okay, read everything Byron said and imagine I said it too, since I agree... saves typing.

...My white wire (Negative) on the truck goes to the frame of the truck and the white wire on the trailer plug goes to the frame of the trailer and I have a ground strap bolted to the tong of the trailer hitch with a big battery alligator clip that I attach to the receiver of the truck, yes, another ground. You can’t rely on the trailer Ball / hitch to provide the ground as many people unknowingly do.

Since the electrical connector from tug to trailer includes a white/ground/negative wire, the strap is a backup to that, rather than to the ball/coupler connection. I don't have a backup for any other circuit, so I don't have one for this circuit... although one could argue that since this is the one circuit which completes all of the others, it deserves special attention and might rate a back-up.

Is the receiver bare steel, Darwin?

...The negative path for all lighting on trucks and autos travels through the frame / body of the vehicle. The battery of the vehicle has the negative side bolted directly to the metal of the vehicle either the frame or engine. The positive side of the battery usually goes directly to the alternator.

All of the truck tail lights I've seen recently mount in those rubber gaskets, and have separate negative wires. All headlights I've seen and all those tail lights assemblies do as well. The negative wire does typically go to a body connection point to take advantage of the metal body in the return path, at least for tail lights, but that only makes sense in a metal-bodied car. Our trailers are a quite different situation - I don't see a problem using the frame, but it doesn't have the same advantage.

The engine starter should not use the body as a return path... there are routinely two "ground" cables or straps, with one direct to the engine.

...When you look at the new vehicles today you will see bolted ground straps all over the place. This is due to the plethora of plastics used and for the manufactures to insure they have quality grounds to every part of the vehicle.

I can believe this (although I haven't noticed any increase in my 2004 van from previous 1980's vehicles), but I suspect it has a lot more to do with electromagnetic interference than with carrying current from the lights.

[Brian B-P]

...When you have a single wire going from light fixture to light fixture (In Series) and attaching in one place to the frame and/or the plug all it has to do is go bad in one spot and nothing else works...

Yes, when the connections are done stupidly (as they are for the marker/clearance lights on my B1700), the serial wiring is a problem. Connecting incoming and outgoing wires to to two points on the same side of the same light socket is asking for trouble, and I was taught that is was not correct for household power wiring. The right way is to connect incoming and outgoing directly to each other with a pigtail coming off to the lamp (or use a tap), just as with the household wiring. In household wiring, wire nuts are used; in a trailer, some form of crimp connector would be more appropriate. The right way, it doesn't matter if the fixture connections go bad, because current for the other fixtures (lights, in the trailer case) doesn't pass through the fixture connection.

Exactly the same problem can occur on both positive and negative sides. I have eleven marker/clearance lights (the regular widebody set, two front, two left, two right, two rear, plus the three-lamp center top ID group). The positive connections daisy-chain through them just as the negative connections do. Even if I ran a separate wire down to the frame from each lamp for the negative side, the positive side would still be subject to failure due to one of the many connections... and I can't fix that with frame connections.

[Byron Kinnaman]

Please note that there is a big difference between a motor vehicle where there is a lot of metal, and as pointed out, newer cars have straps to get around the plastic and a plastic thing (fiberglass trailer).

Your fiberglass trailer is more like a cell phone or plastic flashlight. In the flashlight there's a metal strap coming from the bottom of the flashlight through the switch then to the bulb. That generally from the negative terminal. I guess you could call that ground, if you wanted to.

In items like your cell phone or other portable electronic devices the negative battery is usually common, to us in the electronic industry we call that ground too. But we don't refer to a metal piece stuck on the outside of the decive as ground.

Take a look at this and find the ground. I'm assuming that this typical. Of course there modifications to the electrical systems like Jim did, but I that's the exception.

If look carefully you'll only see ground mentioned once, at the connection of converter. That one is the green wire from the 120 AC system.

The white wire and the black wire coming from the battery and the tow vehicle connector are shown as wires. No connection to ground, the frame, or anything except the fixtures, and appliances.

[Pete Dumbleton]

We're getting wrapped around the axle here.

The return path for the light fixtures is indeed the white wire; there is no frame ground involved in the fixtures, so the white wire is needed. If there is a lighting problem, the first place to suspect is in the white wires. So for FG trailers, I'll modify my "Bad grounds" statement to "Bad return path to battery".

The Scamp trailer frame is grounded to the white wire two ways:

1. By the converter's connection to the 120VAC green wire connection to the frame (the Scamp diagram doesn't show that connection between the green wire and frame).

I wonder what Scamp does if a trailer is built with a battery but no converter/120VAC (I believe recent Scamp converters have the 120VAC breaker box built into the converter so it is all one unit).

2. By the white wire connected to the tow vehicle, which is frame-grounded (albeit poorly) back to the trailer via the hitch components (the Scamp diagram doesn't show that connection either).

Here's a test for that -- Hitch up a Scamp, using some steel wool, etc., on the hitch components (or, better, Darwin's strap) and on the tow vehicle seven-pin socket, remove the white wire to the tow vehicle ground/return. Then check the lights and brakes on the trailer; if they work, there's more to it than just a white wire return path...

If one were to hitch up a tow vehicle with a positive ground system (as some used to be), would one have to make some wiring changes in the trailer to convert it? If so, I would label the original trailer as negative ground.

That's my story and I'm sticking to it!

[Darwin Maring]

With all the grease on the trailer ball and a somewhat rusty ball and socket and a rusty white wire ground on the trailer or tow vehicle, I have had lights sometimes work, sometimes not work and most often flicker because of the return path (Ground) did not complete connection.

Many utility trailers have this problem because Harry homeowner did the wiring and just didn’t know understand the grounding situation.

As far as the negative side of the battery (ground) on the tow vehicle frame – it makes a connection on the trailer frame when you hitch it up therefore the ground (Negative Side) of the tow vehicle battery is physically connected to the trailer frame. Connect things in the trailer wrong and you could have a serious problem. One major problem would be if the AC Park Power were installed wrong (Voltage on the wrong pin) you could apply AC voltage to the chassis (Frame of the trailer and tow vehicle if still hitched up) so it is a safety issue where you should always carry one of those 3 pin AC Circuit testers that light up to inform you if you have the correct wire connected to the correct pin. They are sold at Home Depot, Wally World, Lows, etc.

It will display the following: Open Ground (Green Wire), Open Natural (White Wire),Open Hot (Black Wire), Hot/Grnd reverse, Hot Natural reversed, and Correct. It has 3 lights on it, one red and 2 yellow or green and a chart to inform you what is what.

Grounding in Buildings and Signal Grounds: Went to a Bell Lab presentation where 2 PhDs were going to give a class on grounding and I set there for a hour watching these geniuses argue with each other on the subject. They could not agree.

Grounding gets most complex once you go beyond the basic vehicle and house wiring. Just recently the State of Virginia now requires multiple ground rods on dwellings and out buildings.

Strapping tow vehicle parts to each other and the frame: The straps also stop tempest which is static to the layman.

Brake wires, stop lights turn signals have separate wires and that is called a star pattern.

Brake lights work off the turn signal wire for each side. Running lights work off 1 wire and run in series.

Interior lights also have a return wire however should one not work at night you don’t have to worry about the trooper pulling you over for that.

One Last Thing: I’m wondering, If We Were To Put A Bucket Of Dirt In The Closet in The Egg And Run All Return Path Wires To It And Stick Them In The Dirt – Would That Be Ground?[color=#3366FF]

[Pete Dumbleton]

One Last Thing: I’m wondering, If We Were To Put A Bucket Of Dirt In The Closet in The Egg And Run All Return Path Wires To It And Stick Them In The Dirt – Would That Be Ground?[color=#3366FF]

Har! Only if the dirt is damp...

"Grounding gets most complex once you go beyond the basic vehicle and house wiring. Just recently the State of Virginia now requires multiple ground rods on dwellings and out buildings."

If the soil is dry and non-conductive, then the more ground rods, the better. Also, common use of PVC plumbing in lieu of the older copper and iron pipes means the ground rod(s) by the service entrance is now the only ground.

When I built my house in the '80s, I had to bury a ground wire to connect the drilled well casing to the copper pipes in the slab and then to the electrical service entrance to create a ground in addition to the ground rod.

[Dennis J. Kane]

Ok - So I just got back from campin' for 4 days. I tried for 2 days to get the lights going. Checked all the things you guys mentioned. I found a white wire and a brown wire joined and screwed to the frame. I opened the panel and looked at the wires where the back of the fridge is. After the wire pass thru from left to right and head to the back, these two wire leave the fiberglass and join together and screw to the frame. i took it off and cleaned it up and scraped the fram and put it back. Nothing! I decided to run during the day with no lights and have all news wire put in when I get back. So I hooked up for the run home today and everything came on. Perfect. Brakes and blinker and everything.

Makes me crazy!