Installing new tail lights

[Cajunguy71]

Greetings, all. I'm new to the group and in need of a little assistance. I have a 1985 Terry Taurus and decided, since the original lens cap was broken, to switch to LED lights. I bought the lights and noticed they had three wires, brown, green, and white. The trailer however has has brown, 2 greens and two Whites. I tried I connected the wires, according to colors, and it acts sporadic at best. It was at one time only working when lights on the tow vehicle were on. Then once the brakes were pushed, goes out completely, and now does nothing at all. I checked the fuse and the grounding point on the frame. All seems well. Any thoughts would be greatly appreciated.

Doug

[Huntindog]

Fisherman wrote:
Are we talking about DC LEDS here?


Well I'm sure he wouldn't be stepping on the brake pedal to try his interior lights. I don't know of any trailers with AC tail lights.

Thats what I thought... For a while there.. I thought I was on a home electrical forum.:B

[Fisherman]

Are we talking about DC LEDS here?


Well I'm sure he wouldn't be stepping on the brake pedal to try his interior lights. I don't know of any trailers with AC tail lights.

[Huntindog]

Bobbo wrote:

deltabravo wrote:

Huntindog wrote:
Often when switching to LEDS, the vehicle wiring needs to have the polarity reversed for the LEDs to work.

I've messed with hundreds of LEDs in my job. The above has never been the case.

LED lights for AC circuits are not polarity sensitive. LED lights for DC circuits usually are polarity sensitive. I have had to reverse the light bulb in a DC circuit to get it to work because of polarity.

Are we talking about DC LEDS here?

[Huntindog]

Try asking the seller of the bulbs. They have a vested interest in making sure they work for you.

[enblethen]

Just for clarification:
What is make and model of the replacement light assemblies? Major brands such as Bargman and Peterson quality is good. Wiring is straight forward.
A little work would be applying 12 volts DC to the trailer connector to the wires in question. Green wire with power applied at connector should turn on right lamp. Powering brown wire should turn on all clearance and tail lights.
Better then checking via TV as it could be wired different then normal TV wiring.

[deltabravo]

Cajunguy71 wrote:
Will try the polarity reversal when I get off work today. Will let you know how it turns out.

Polarity reversal on a tail light is not going to fix the problem.... it's going to create more problems.

A tail light / brake light is polarity sensitive.

On a tail light you have three wires:
Ground
Tail light
Brake / turn

You simply can't switch polarity and expect it to work when you have two positive connections and one ground connection.

[Bobbo]

deltabravo wrote:

Huntindog wrote:
Often when switching to LEDS, the vehicle wiring needs to have the polarity reversed for the LEDs to work.

I've messed with hundreds of LEDs in my job. The above has never been the case.

LED lights for AC circuits are not polarity sensitive. LED lights for DC circuits usually are polarity sensitive. I have had to reverse the light bulb in a DC circuit to get it to work because of polarity.

[Cajunguy71]

I appreciate the input guys. Will try the polarity reversal when I get off work today. Will let you know how it turns out.

[Huntindog]

deltabravo wrote:

Huntindog wrote:
Often when switching to LEDS, the vehicle wiring needs to have the polarity reversed for the LEDs to work.

I've messed with hundreds of LEDs in my job. The above has never been the case.

It is quite common, and well known. LEDs are polarity specific.... Just go to LED sellers websites, and they often state this... The most common problem sellers have, is customers wanting to return perfectly fine LEDs that they think are defective.... But they just need to reverse the polarity.

[STBRetired]

Did mine on the MH a few years ago. Don't remember exactly which wire was witch but they did not match the existing wires from the old lights. I seem to recall that the black was the ground, not the white. Ended up just taking the light up to where the battery was to figure out which wire did what.

[deltabravo]

Huntindog wrote:
Often when switching to LEDS, the vehicle wiring needs to have the polarity reversed for the LEDs to work.

I've messed with hundreds of LEDs in my job. The above has never been the case.

[Huntindog]

Keep in mind that incandescent bulbs don't care about polarity.... LEDS do. Often when switching to LEDS, the vehicle wiring needs to have the polarity reversed for the LEDs to work.

[enblethen]

This may help!
Generic trailer wiring diagram
It shows right tail light feed rear clearance lights. However I doubt it on your rig.

[enblethen]

No, the second wire goes to tail light. The first ground may go to the area around the tongue where the umbilical cord connects to the trailer wiring. The white wires should be connected at that point to the TV cord.
Green in your right side light as three wires in my thinking. One to the front of the rig, one to the left side light. There would be three green wires connected together and three whites connected together.