Scamp Taillights Acting Funny

[AC0GV]

Originally Posted by brettrae

Not yet...I wasn't sure what you meant by that. Are you talking about attaching an alligator clip from the 12V battery power pin on the Scamp's 7 way connector to every other pin on that same connector, aside from the ground? I just wanted to make sure that I understood you. If so, I'll try that tomorrow and see what comes on.

Yes that should light the lights on that circuit only. 4 to 3 marker and tail lights, 4 to 5 left stop/turn, and 4 to 6 right stop/turn. I have also used an amp meter set to 10 amps for a jumper but if you get 12 vdc to ground it will blow a fuse or the meter. The picture is measuring brake current.
Good luck

[David B.]

We had the very same problem with our 13’ Scamp. I took a wire and held it to the tail light housing and the other end to the bumper (scratched off the paint to bare metal) and everything straightened out. I then simply cleaned up all the ground connections and it fixed the problem.
Good luck with yours.
Dave & Paula

[brettrae]

Per Kenneth's suggestion, I jumpered from the 12v pin on the trailer plug to the other pins. Here's what lit up when I jumpered to the following:

Tail and Running Lights (pin 3): the bottom bulb (taillight) on the right side stayed lit. Nothing else.

Left Turn and Break (pin 5): the top bulbs (back up lights?) on both sides stayed lit.

Right Turn and Break (pin 6): the bottom bulbs (taillight) on both sides stayed lit. The back (red) running lights also stayed lit.

[brettrae]

Originally Posted by David B.

We had the very same problem with our 13’ Scamp. I took a wire and held it to the tail light housing and the other end to the bumper (scratched off the paint to bare metal) and everything straightened out. I then simply cleaned up all the ground connections and it fixed the problem.
Good luck with yours.
Dave & Paula

Are you talking about the ground connections on the back of the light fixtures?

[brettrae]

Here are some photos of the wires coming into the Scamp, under the front bunk. And then coming into the Scamp from the taillights, under the rear dinette benches. I didn't know there was a fuse there...there's also one coming out of the battery. Would it be worth it to undo the quick wire splices (blue box in 2nd pic) and redo all of the connections with heat shrink as I work my way down the line? I'm going to unwrap all of the electrical tape and inspect for frays, etc.

[AC0GV]

Originally Posted by brettrae

Here are some photos of the wires coming into the Scamp, under the front bunk. And then coming into the Scamp from the taillights, under the rear dinette benches. I didn't know there was a fuse there...there's also one coming out of the battery. Also, any idea what those little blue plastic boxes are in the second picture? They're some sort of wire connection, but I'm not sure how to inspect them. I'm going to unwrap all of the electrical tape and inspect for frays, etc.

Yes, some had a second battery fuse under the bunk, but that tape may not be factory.
The little blue boxes are Insulated Crimp Terminals and are OK inside out of the weather.They have a little cover over them that opens up.


If the grounds are good at the lights ( that test where you connect the outside of the sockets to the frame) My guess would be that someone destroyed the seven pin cable to the tow vehicle and wired it wrong when they replaced it. If it were mine, I would disconnect all the wires and reconnect them one at a time watching for the correct lights to light. If you are not that brave, you could also trace the wire colors as given in the back of the book. With the added wires and the crimp taps it looks like the former owner was trying to do something that the Scamp was not meant to do.

[David B.]

Originally Posted by brettrae

Are you talking about the ground connections on the back of the light fixtures?

Yes. If the tail lights are not well grounded, you will have very odd light show.
Dave & Paula

[brettrae]

Okay, today I'm going to test the grounds at the lights to see if that's the problem. If not....well, I'll make a plan for that once I get there. One step at a time! haha this is all relatively new for me, so I'm learning as I'm going. It's fun sometimes and infuriating others, BUT I'll definitely know my Scamp better by the end of this!

[gordon2]

Originally Posted by David B.

Yes. If the tail lights are not well grounded, you will have very odd light show.
...

But how could a bad ground cause this?....

Originally Posted by brettrae

... the left turn signal will turn on the emergency flashers and the right turn signal won't do anything at all. ...

Underline added to show focus.

[alan H]

Originally Posted by gordon2

But how could a bad ground cause this?....





Underline added to show focus.

Please be sure and post what you have found to be the problem
This is an issue that I’m guessing has a lot of followers

[Lynn Eberhardt]

"But how could a bad ground cause this?...."

If all bulbs don't have a good ground, current will follow the path of least resistance, like water does, and that's often back through another bulb filament, causing quite a "light show."

[gordon2]

Originally Posted by Lynn Eberhardt

"But how could a bad ground cause this?...."

If all bulbs don't have a good ground, current will follow the path of least resistance, like water does, and that's often back through another bulb filament, causing quite a "light show."

But how would it activate the tug's four way flasher? Or do you think the OP saw something that looked like the vehicle's flasher was on?

[brettrae]

Originally Posted by gordon2

But how would it activate the tug's four way flasher? Or do you think the OP saw something that looked like the vehicle's flasher was on?

I'm sorry, I believe I may have misspoken and confused you. I didn't mean that it turned on the tug's for way flashers. I was referring to the top light bulbs in the Scamp. I have now learned that those are simply the back up lights.

[brettrae]

UPDATE: I ran a jumper wire with alligator clamps from the metal casing behind the lightbulbs to the frame of the Scamp (which I had sanded to bare metal). Then I plugged in the tow and tried the lights....that didn't fix the problem. This time, the right turn signal on the truck caused both taillights to flash and the left turn signal on the truck caused both back up lights to flash. This is different than before, but still not right, obviously. Does that mean it wasn't a ground issue from the lights?

[Lynn Eberhardt]

Here's how things should be wired.
Use it for reference when you're trying to determine what really goes where.
You may already have this diagram, but now you do for sure.

[David B.]

Originally Posted by brettrae

UPDATE: I ran a jumper wire with alligator clamps from the metal casing behind the lightbulbs to the frame of the Scamp (which I had sanded to bare metal). Then I plugged in the tow and tried the lights....that didn't fix the problem. This time, the right turn signal on the truck caused both taillights to flash and the left turn signal on the truck caused both back up lights to flash. This is different than before, but still not right, obviously. Does that mean it wasn't a ground issue from the lights?

Had you only placed the new ground to only one of the tail light housing, or both?

[k corbin]

Just start at the tail light fixture itself. Check inside all of the light bulb sockets looking for any signs of corrosion. Next check the ground wire connection that fastens to the metal housing.

Next look at the wire connections where the wires from the tail light connect to the tail light wiring harness. Take photos, make notes, add labels to the wires noting which wire is going to which bulb function.

I do not like any of the types of splices I am seeing in your photos. They should all be replaced with good quality, marine grade crimped on insulated splices. They way they were done in the factory was to save labor cost and material cost. You can take the time to upgrade that job to something much more reliable.

Then follow along the wires to find the next connectors on the wires and replace those as well being sure to add labels to both sides of the wire at any connections including where the ground wires are fastened to the frame. At that ground connection you should remove then fastener and inspect for corrosion, clean it off if needed, replace the ring terminal at the end of the ground wire if it looks corroded.

You will eventually reach the plug connectors that tie the trailer to the tow vehicles. Inspect those carefully for any signs of corrosion within the pins and receptacle tubes. If you see a lot of corrosion you can try cleaning it up or just go ahead and put new plugs on.

At this point in time you will be following the wire up to the vehicle tail light wiring harness. You can also inspect that and if needed upgrade with new wire splices. To inspect further into the tail light wiring harness you should obtain the repair manual for your tow vehicle which shows how those wires are run and where the location of the fuses for that wiring are.

This whole process is very systematic, you start at one end and work towards the other end. It is not particularly difficult to do. Just work methodically and safely.

[brettrae]

Originally Posted by David B.

Had you only placed the new ground to only one of the tail light housing, or both?

I attached an alligator clip to the metal plate behind the bottom lightbulb and then attached the other end of the jumper to the bare metal on the frame. I did this to both light fixtures, simultaneously. Would I need to jumper every lightbulb to the frame (4 total) in order for this test to work?

I'm also not sure if this proves anything, but I tested continuity with my meter from the metal plate behind the lightbulbs to the frame of the Scamp, and there was good continuity between the two.

[brettrae]

I think what I'll do now is order some of these heat shrink 3-way terminals (https://www.amazon.com/16-14-Heavy-H.../dp/B00NVA8ES6) to replace the insulated crimp terminals and a set of heat shrink terminal connectors and just work my way down the line replacing everything as I go. I'm also probably going to go ahead and order a new set of LED taillights and runners...might as well do that while I'm at it!

[Radar1]

This probably won't fix your lighting problems but I got tired of that rats nest of taped and scotch-locked wires in the front of the Scamp and installed a box for better connections like this one.
You mentioned that you might be replacing the lights with LED fixtures, that should solve any corrosion problems and you'll then be able to insure that the wires are connected properly.
Sorry to hear about the problems, electrical problems can be hard to figure out sometimes.