[pdxman1]

I have a 2012 Outback and just installed a Curt 56040 T-Connector Wiring Kit. I have LED trailer lights on my trailer. I was testing it and everything seemed to be working, but I noticed that one LED on each light remained on even after I turned the ignition off. (Normal operation for the LED taillights is multiple LEDs are illuminated for the tail lights, brake lights and signals.)

So I disconnected the trailer checked the voltages on the connector (flat 4-way connector) and each of the wires has 12V present even when the ignition is off.

Is that normal? Obviously that means there will be some battery drain if I leave the trailer connected. I wonder if the adapter is causing battery drain when the trailer is not connected.

 

[subiesailor]

That is strange - my first guess is that the mixer box is goofy ie faulty and some how bleeding power from a hot wire from the car.

Mine doesn't do that LED should not matter of course.

 

[plain OM]

ditto, sounds as if the adapter is faulty.

One of the six wires on the car's trailer harness going to the adapter is an always-on 12V. This is needed so that the trailer brake lights can work even with the ignition key out when most other lights, such as turn signals and tail/clearance do not. That's where the 12 V is coming from.

The adapter, however, should not pass any voltage through to the 4-pin trailer connector except when one of the related car functions (stop light, tail lights, turn signal) is being used.

Be sure that the six pin connector from the adapter has been inserted properly into the connector on the car wiring harness, and not reversed (difficult to do because of shape, but who knows . . .).

 

[pdxman1]

That is strange - my first guess is that the mixer box is goofy ie faulty and some how bleeding power from a hot wire from the car.

Mine doesn't do that LED should not matter of course.

Thanks, but how do you know yours doesn't have voltage present? Did you check the voltage? I suspect that if I had regular lights instead of LEDs, I would not even have known. I don't think that enough current is flowing to light up regular bulbs.

 

[pdxman1]

ditto, sounds as if the adapter is faulty.

One of the six wires on the car's trailer harness going to the adapter is an always-on 12V. This is needed so that the trailer brake lights can work even with the ignition key out when most other lights, such as turn signals and tail/clearance do not. That's where the 12 V is coming from.

The adapter, however, should not pass any voltage through to the 4-pin trailer connector except when one of the related car functions (stop light, tail lights, turn signal) is being used.

Be sure that the six pin connector from the adapter has been inserted properly into the connector on the car wiring harness, and not reversed (difficult to do because of shape, but who knows . . .).

I just called Curt Technical Support. They said that it was normal and that so little current is flowing that the trailer could be hooked up for months without draining the battery.

Kudos to Curt, by the way. The call was answered quickly and I don't think they have outsourced their call center. I am so used to long wait times and poor support from manufacturers, that I usually call them as a last resort.

 

[plain OM]

Months?

A single LED usually draws about 20 ma at rated brightness (can draw more, or less, with change in brightness). If, say, there's four LEDs on all the time, that could be 80 mA. (Could be different; depends on how the LEDs in each set are wired.) Your car battery probably has a capacity of about 50 Amp hours; that's 50,000 mA-hours. A fully charged battery would be discharged after 625 hours (assuming constant current drain), or about 26 days. Not quite a month.

I'd be interested to learn whether other adapters used with LED-equipped trailers are the same.

 

[subiesailor]

Months?

A single LED usually draws about 20 ma at rated brightness (can draw more, or less, with change in brightness). If, say, there's four LEDs on all the time, that could be 80 mA. (Could be different; depends on how the LEDs in each set are wired.) Your car battery probably has a capacity of about 50 Amp hours; that's 50,000 mA-hours. A fully charged battery would be discharged after 625 hours (assuming constant current drain), or about 26 days. Not quite a month.

I'd be interested to learn whether other adapters used with LED-equipped trailers are the same.

If the constant power leak is truly a by product of the converter box it doesn't matter if you have a LED equipped trailer or a old school bulb trailer your still leaking power.

I will say one thing the old REESE converter box I've had on two different cars over the years same box - was on my subaru that sat for 4 months and the car started though it was a very weak battery it did start - however! The trailer plug was not plugged into anything.

I have whatever converter box hidden hitch sold me so I could go and check it see if it leaks power also. I can't imagine there being multiple makers of this box all the boxes are probably made by one or two electronics outfits then sold under different brands.

 

[pdxman1]

Months?

A single LED usually draws about 20 ma at rated brightness (can draw more, or less, with change in brightness). If, say, there's four LEDs on all the time, that could be 80 mA. (Could be different; depends on how the LEDs in each set are wired.) Your car battery probably has a capacity of about 50 Amp hours; that's 50,000 mA-hours. A fully charged battery would be discharged after 625 hours (assuming constant current drain), or about 26 days. Not quite a month.

I'd be interested to learn whether other adapters used with LED-equipped trailers are the same.

I don't think that the two LEDs that were lit were at full brightness, so that would reduce the current draw. I could check the current draw, but I don't leave my trailer hooked up for long periods of time, so I don't think I'll bother. I'm actually more interested in knowing how much current the adapter draws when the trailer is not connected, but I'd have get to the adapter to do it and it would be a pain to get to it.

I'm also curious to see if other adapters exhibit the same behavior. That is pretty simple to test - all you need is a voltmeter.

 

[lavarock]

I installed a 118467 T-One wiring harness I got at Etrailer T-One Vehicle Wiring Harness with 4 Pole Trailer Connector - Subaru Forester and Outback Wagon Tow Ready Custom Fit Vehicle Wiring 118467
I measured voltages with key out of car and doors closed. I used a Fluke 87 digital voltmeter. I measured about 50 mv. That is basically zero volts as the fluke has an input impedance of 10 meg ohms.
This was on my 2012 Outback 3.6R

 

[John E Davies]

I have a trailer with LEDs and have never observed the "glow". My OB has the OEM adapter that came with the receiver.

If you have a meter with milliamp measuring capability, you would have to fabricate a short test harness to plug in between the trailer connector and the car connector. The meter must be connected in series with the wire being tested, and you don't want to cut your trailer harness.

I would do this, for peace of mind if nothing more... Sure you can unplug the trailer when not towing, but if you forget and several days pass, it might be an issue.

Remember these words of wisdom: almost ALL trailer lighting problems are due to a poor or nonexistent ground circuit. It's best to run small ground wires for each and every trailer light to a common ground stud on the frame, and from there a single large gauge ground wire to the trailer connector. Don't rely on the coupler to ball connection for a current path! I used a couple of stainless terminal strips from West Marine to (completely!) rewire my trailer when I bought it new in 2002. I coated all the connections with liquid electrical tape (from NAPA or Wally World). In the years since, I have not had a single lighting related problem.

Do you have one of these? They are cheap and very handy for checking your car's wiring before a trip:

John Davies
Spokane WA USA

 

[AAP4716]

I installed the same Curt connector. I hooked up the trailer last night for the first time and after turning the ignition off, I noticed the same thing. My trailer has 6 LED's on each brake light. All 6 were VERY dimly lit.

 

[notsubiesailor]

Curt T-Connectors

I have a 2012 Outback and just installed a Curt 56040 T-Connector Wiring Kit. I have LED trailer lights on my trailer. I was testing it and everything seemed to be working, but I noticed that one LED on each light remained on even after I turned the ignition off. (Normal operation for the LED taillights is multiple LEDs are illuminated for the tail lights, brake lights and signals.)

So I disconnected the trailer checked the voltages on the connector (flat 4-way connector) and each of the wires has 12V present even when the ignition is off.

Is that normal? Obviously that means there will be some battery drain if I leave the trailer connected. I wonder if the adapter is causing battery drain when the trailer is not connected.

I have the exact same result with my Curt T-Connectors. I just installed a Curt 56162 T-connector (flat 4-way connector) set on a 2009 Dodge Van. I haven't used the trailer for about 8 months, and when I connected it, I saw no turn signals or running lights working. I disconnected that trailer, and checked the vehicle connector right away with a voltage meter, and it read 12 volts at each connection (right/left turn & running lights) with the van turned off and no lights on. Even when a turn signal was activated, there was no pulse showing on the voltage meter, just a continual 12 volts. I was worried there was a problem with the powered converter box. Further checking with a 12 volt test lamp showed everything was just fine. There is still always 12 volts at each connector, but not enough current to light anything when the van is turned off. It turned out that my trailer lights were just poorly grounded, so I fixed that. Glad I saw your post, so I know this is normal for Curt. Thanks.