Something odd is going on!

[GaryJ]

My wife came in a few weeks back and said our tear's tail lights were on. I thought this was impossible because it was not plugged into the car. Well they were glowing when I checked. What could cause this? It only happens when my battery reaches a full charge. I have a Inteli Converter with a charge wizard that I use to keep my battery topped off. I do have the trailer lights plug grounded to the tounge and the converter is grounded to the frame as per the instructions. I would not think that would cause this. I can unplug the shore power and draw the battery down and everything is normal. Plug in the shore power and all is well. I can use the 110 or 12v with no glowing tail lights. Leave it plugged in and as soon as the charge wizard shows the battery is charged the tail lights glow! Well at at least I know when it's charged!

[Dale M.]

Should no happen because tail/stop lamp wires should be totally isolated (separate circuit) from and on board 12v supply or shore power or battery charging situation.... Someplace along the line you have a wiring error....

Just having a "common ground" (the chassis) should NOT cause this...

Dale

[GaryJ]

I ran the trailer lights last so I know it is completely seperate. It's got me baffled. If it were something wired wrong I would think the lights would glow anytime the shore power is plugged in. This only happens when the battery is right at full charge.

[Corwin C]

There's definitely an issue here somewhere ... do the lights go out if you disconnect the positive side of the battery? (Don't laugh, but I've chased a "glowing light" problem for over a half hour that was actually sunlight bouncing around in the lens.) I would definitely find the issue and/or remove the battery until you solve it (wouldn't want to cause a fire).

I would re-establish each positive connection one at a time and see which one is crosslinking to your tail lights. Hopefully this will help you narrow it down. My suspicion is that you have a positive wire that has shorted to one of your tail lights in some fashion.

You could also use a multimeter at the plug that connects to your car and find the one with voltage (except for the battery charge connection) and trace it back that way.

Another possibility (and the hardest to find) is if something has a bad ground and it is using your tail lights to get to ground. If so, you have a problem with both the trailer lights and another load in the trailer.

Best of luck ... let us know what you find.

[eamarquardt]

In order for your lights to come on you have to have a complete circular circuit. So the positive side of your battery is getting to the positive side of your bulbs and the negative side of the battery is getting to the negative pole of your battery. Pretty simple.

Some thoughts to narrow it down:

When the trailer's lights are on (and shouldn't be) unplug your converter and see if that makes a difference.

Perhaps undo one bulb at a time and see if things change.

If each bulb has a pair of wires to a common point or points, disconnect the wiring for each bulb one at a time and see if things change.

Use a meter and see if there is continuity from your connector on your trailer that goes to the vehicle light circuit and your trailer's positive terminal. I would think there shouldn't be a connection.

Perhaps one of these tests will point you in the right direction.

Hope this helps.

Cheers,

Gus

[PaulC]

Sounds to me like you've reverse earthed one of your taillights. I'm thinking one light has earth to earth but the other has positive to earth. This would enable a completed, low voltage circuit to happen. It sounds like and earth leak thing so check all your earth points. It also sounds as though it is only low voltage leakage.
Cheers
Paul

[eamarquardt]

Sounds to me like you've reverse earthed one of your taillights. I'm thinking one light has earth to earth but the other has positive to earth. This would enable a completed, low voltage circuit to happen. It sounds like and earth leak thing so check all your earth points. It also sounds as though it is only low voltage leakage.
Cheers
Paul

What exactly is a "reverse earthed" taillight?

Gus

[PaulC]

Sounds to me like you've reverse earthed one of your taillights. I'm thinking one light has earth to earth but the other has positive to earth. This would enable a completed, low voltage circuit to happen. It sounds like and earth leak thing so check all your earth points. It also sounds as though it is only low voltage leakage.
Cheers
Paul

What exactly is a "reverse earthed" taillight?

Gus

Gus, read my post again my friend. It is explained as to what I mean in it.
Cheers
Paul

[Dale M.]

Sounds to me like you've reverse earthed one of your taillights. I'm thinking one light has earth to earth but the other has positive to earth. This would enable a completed, low voltage circuit to happen. It sounds like and earth leak thing so check all your earth points. It also sounds as though it is only low voltage leakage.
Cheers
Paul

Dont think you "theory" is valid.... Most incandescent lamps are either continuity or not (and not polarity sensitive)... "Not" as in off or broke filament ... Or on as ground on one side and power on other.... Reversed earth and reversed parity are one and the same, only lamps I am aware of that are effected by reverse parity are LED... Wired correctly they light, wired "reversed" they do not light....

Biggest problem with lighting is poor grounds and "ground feed back"...

Besides how does tail lamp circuit supposedly isolated from TD "power" light from TD battery...

Dale

[bobhenry]

I have to agree with dale.........

"Biggest problem with lighting is poor grounds and "ground feed back"...

Looks like a bolt together trailer and we have chased this rabbit around the barn before. The quickest and easiest way to check that I can think of is make up a pair of 3-5 foot electrical wires with a large size spring clamp
( alligator clip) on each end of each wire. Clip one end of each to both of the bare metal barrels of the light socket and both other ends to a known good ground. After both light have been redundently grounded the problem ( in my opinion) should disappear.

Let us know what happens !

[zipz71]

First of all check your grounds as mentioned above. I brought all of mine to a common point on the frame close to the battery.

Are your lights led? Are they coming on bright or dim?

I've noticed that my taillights (led) glow faintly when the plug is wet. The moisture is creating a circuit between the 12 v charging pin and the taillight pin in my 7 pin connector. This is the only place on mine that the 2 circuits are close to each other. After the grounds I would look here. Even a small amount of corrosion inside the plug can create a path for current to flow.

[GaryJ]

I think you may have hit on something zipz71. I was going to disconnect the wire that goes from the battery to the charging pin tonight. I was thinking there might be some bleed over in the plug somehow when the battery reaches full charge. My tail lights are led and it is a faint but noticeable glow. They go out as soon as the shore power is unplugged. The running lights are not led and they do not glow. I'm pretty sure I'm well grounded. (no matter what the wife says) Thanks to all of y'all for the help!!! It's great to have a place to come to for help from folks in the know!

[GaryJ]

I disconnected the charging wire on my 7 pin connector from the battery. No more glowing taillights!