12 v LED connection


Old 01-15-20, 07:49 AM
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12 v LED connection

I want to add a 12 volt LED light in the open end of my cargo carrier. I plan on buying this…


and powering by taping into one or more of a standard flat 4 connector trailer side to the cars hitch electrical plug.

With the choice of using :

Brown: tail lights ;will only be on if night time driving lights are on

Green: right turn signal and brakes

Yellow: left turn signal and brakes

White: ground

What I would like is for the light to be actuated when stepping on the brake (do I just connect to the left or right or both, and how does this affect just a turn signal actuation), and to be continuously on at night with the night driving lights on. Would or could I connect to all three? If I can’t get all three I’ll go with the Brown and just have it lite at night.
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Old 01-15-20, 11:38 AM
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really only going to be able to get tail lights probably with that light, if you wanted brake would look for a light with more wires thats designed for multifunction like brake and tail even then you may have to hook into the third brake light to get it to function correctly.
Old 01-15-20, 11:42 AM
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You'll need something else to make it work with only one LED. With a trailer the decision to make left or right blink or both turn on is done by the vehicle. With only one light you need some logic in the mix that will say if the green and yellow are BOTH energized at the same time then turn on the LED. I don't know of a ready made product to do that.

You can use old fashioned relays or go modern and use an Arduino to control when to turn on the new brake light. Amazon and many other places sell Arduino kits though you'd still have to learn some programming and have a little control box buried somewhere in the tow vehicle. The Arduino would need a constant source of power in addition to tying into the green and yellow wires of your 4 pin trailer connector.

The simplest option I can think of is to tie into your vehicle's wiring for the third brake light. Run the wires and a connector down by the receiver to power the new brake light on your carrier. Whenever your vehicle's third brake light is illuminated so would the light on your carrier rack.
Old 01-15-20, 02:57 PM
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I was hoping to plug into the trailer harness, to keep it simple. So I'll go with the brown and just use tail lights. Which is fine since at night the cargo carrier is nearly invisible. I also will be pasting on lots of reflectors. I could put on a whole multi function light bar on the unit. But my intent was to cover the hole to prevent dirt and debris from entering the tube. The light was just an after thought and another way to waste time and plastic with my printer.

How about this. Will using just one of these do what I want?

Meerkatt (Pack of 4) 3/4 Inch Small Red LED Round Side Marker Indicator Lights Bullet Shape with Rubber Brake Stop Tail Lamp Multi-Function for Camper Pickup Trailer RV Truck Van Jeep 12V DC 3led-HL


I also found this:

Old 01-15-20, 06:09 PM
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You need a 2w to 3w taillight converter. There are many around for incandescent.
I'm trying to find one for LED.

Here's a standard one..... converter

The converter takes left directional in, right directional in and ground and converts it to left directional out, brake out and right directional out. You just use the brake (red) wire.

This one will work because it uses switching relays.
BTW.... you can connect it to your flat four pin connector.
Old 01-16-20, 06:07 AM
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Thanks Pete. Now I understand why. Not worth the expense. But I'm glad to know that the parts are available.
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