Right LED tail light staying on

[Carrera_man]

Here's an unusual problem that has cropped up in the past week. Can't get my right LED tail light to shut off. The trailer is not plugged into my truck. The only way I can get it off is to disconnect the house battery. I thought 12 volt house current is separate from truck 12 volt. I did hook it up to my truck and all lights work, except still can't shut off the right rear.
Its not as bright as it normal would be, almost like its picking up residual current from something. The right LED taillight is the only light that has this problem Any ideas?

[enblethen]

Easy fix and not to expensive to buy new connector.

[wnjj]

That's great news that you've found it. Thanks for getting back to the thread and not leaving us hanging like so many do.

[Carrera_man]

Well I believe I found the problem. As some of you have suggested the problem is in the seven way plug. Checked the terminals, the right light was getting 4 volts. Sprayed the plug with DeOxIt electrical contact cleaner. Rear light got very dim, voltage went down to 2 volts. Rapped the plug a bunch of times against the frame, light went out, voltage went to zero. This plug is a molded plug onto the wire so that's why I couldn't take it apart. I suspect moisture get into it one way or another creating corrosion. We had a tough winter here this past year and it pretty much stayed below freezing for about 8 weeks. When our thaw happened last week is when the light came on. I'll replace the plug in a week or two just for the heck of it and cut the old one apart to see if I could find what problem was. A big thank you to everyone for taking the time to give me your opinion!

[beemerphile1]

Probably a stray strand of wire in the seven-way connector.

[enblethen]

Dusty: You could have some poorly insulated connections or corrosion in lamp sockets or trailer connector allowing for slow drain on battery.

[Bobbo]

You need a diode to restrict the current flow of the charge line to one direction, toward the battery.

[Dusty_R]

Different problem but might be the same.
I have a 20' flat bed trailer with break way brake system with it's own battery. That system charges it's battery when in use. But for some reason it will drain it's battery when sitting, not plugged in and sitting for a long time. I have to remember to unplug it's battery when not in use. Then remember to plug the battery in when I use it.

Before I had a smaller trailer with break away brakes, but it did not have the charging system and it never drained the battery between uses.

Dusty

[MEXICOWANDERER]

Artum Snowbird wrote:

enblethen wrote:
I would check your connector to the TV on the trailers umbilical cord. You may find corrosion between the 12 volt line and the right "brake" light.
The other place other than wiring is the junction box where the umbilical cord connects to the trailer wiring.

I agree with this diagnosis. The 12 volt feed is right next to the right turn/brake feed. LED's take so little current that the opportunity to sneak across if the insulation breaks down is quite likely.

Mee Three

[RLS7201]

Carrera man wrote:

RLS7201 wrote:
What you are experiencing is an electromagnetically induced voltage. I had the same problem on my MH when I added LED tail/stop lights. A little resistance between the hot leads and ground will bleed off the induced voltage. I added a 912 incandescent bulb to each side behind the tail lights to bleed of the stray voltage. In my case the stray voltage caused the cruse control and torque convert clutch to malfunction.


Richard
95 Bounder

LED's came with this trailer. Trailer has been sitting plugged in since the end of October. Problem didn't start until last week and only on the right taillight. I would agree with those here if more then one light was effected about a ground or stray voltage. It sure does sound like, as some have commented, that its a problem in the cable going to the truck or the box that cable is connected to. That will be my first place to start.

I stand corrected. I misread your original post.

Richard

[Carrera_man]

RLS7201 wrote:
What you are experiencing is an electromagnetically induced voltage. I had the same problem on my MH when I added LED tail/stop lights. A little resistance between the hot leads and ground will bleed off the induced voltage. I added a 912 incandescent bulb to each side behind the tail lights to bleed of the stray voltage. In my case the stray voltage caused the cruse control and torque convert clutch to malfunction.


Richard
95 Bounder

LED's came with this trailer. Trailer has been sitting plugged in since the end of October. Problem didn't start until last week and only on the right taillight. I would agree with those here if more then one light was effected about a ground or stray voltage. It sure does sound like, as some have commented, that its a problem in the cable going to the truck or the box that cable is connected to. That will be my first place to start.

[RLS7201]

What you are experiencing is an electromagnetically induced voltage. I had the same problem on my MH when I added LED tail/stop lights. A little resistance between the hot leads and ground will bleed off the induced voltage. I added a 912 incandescent bulb to each side behind the tail lights to bleed of the stray voltage. In my case the stray voltage caused the cruse control and torque convert clutch to malfunction.


Richard
95 Bounder

[Carrera_man]

Great info here.
I'll check these suggestions this weekend, hopefully the weather will be decent enough for me to do so.
Thanks everyone, I'll post what I find.

[wnjj]

This guy was having the same issue (but without LED) lights. Like his, I'm suspecting an issue in the 7-pin plug. In your case, it only takes one loose strand of wire to touch the 12V pin and light up an LED bulb.

The power for the turn and tail lights normally comes only from the TV but the connector also has the 12V charge wire from the truck which is connected to your trailer battery.

[Artum_Snowbird]

enblethen wrote:
I would check your connector to the TV on the trailers umbilical cord. You may find corrosion between the 12 volt line and the right "brake" light.
The other place other than wiring is the junction box where the umbilical cord connects to the trailer wiring.

I agree with this diagnosis. The 12 volt feed is right next to the right turn/brake feed. LED's take so little current that the opportunity to sneak across if the insulation breaks down is quite likely.