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Discussion Starter · #1 ·
Hello All. I am new to the forums but we have owned our 2013 sienna SE for six years now. I searched the site and could not find anything about what I would like to do. I know from the factory the brake light and tail light (the lights on the hatch) do NOT light up together. The design on the SE lights looks like both brake and tail lights should turn on together. I spent an hour this afternoon fiddling with the blue wires (power for brake lights) and the brown wires (power for the tail lights). How do I rewire it so brake lights and tail lights turn on when the brake pedal is pressed?
 

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I am thinking you will run into issues when you turn on your running lights and may backfeed into the brake light circuit if you do this.
MIL on. P0606 code. Not sure if it is worth it in the end.

Just my $0.02
 

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Discussion Starter · #3 ·
I am thinking you will run into issues when you turn on your running lights and may backfeed into the brake light circuit if you do this.
MIL on. P0606 code. Not sure if it is worth it in the end.

Just my $0.02
Yeah … the best I could get was with the running lights off, brake lights and tail lights. HOORAY! With the running/driving lights on, the brake lights are on … all the time. Sigh.
 

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A diode should keep the tail circuit from backfeeding that brake light.
Two diode are needed, and the hatch taillights can be used as stop lights.
Slope Font Parallel Handwriting Rectangle

The diode from the stop to taillights will let the taillights light up when the stop lights are pressed, but keep the taillights from back feeding and turning on the stop lights.

The diode before the tail lights will let the taillights function as taillights, and keep the stop lights from back feeding and turning on all the the rest of the running lights in the van (corner markers, front parking lights).

I believe this is what the OP wants. I couldn’t sleep so I was browsing threads and found this.

However, I’m not sure how useful this will be. The hatch taillights aren’t very visible in the daytime, and this setup won’t let them get brighter at night when they are already running as taillights and you press the brake.

Also to be noted is the wire gauge of the stop lights is very small, as they drive LEDs. The hatch taillights are halogen. However, they are only 5 W bulbs so this likely isn’t an issue.

The diodes will make the taillights slightly dimmer, probably imperceptibly so, but this is due to the voltage drop diodes have of 0.7 volts for a standard diode. Schottky diodes could be used for a lower voltage drop of approximately 0.2 volts.

This reminded me of something I made in 2012. I had a Kia Spectra with separate stop and turn lights, and wanted to tow a small utility trailer. I got a simple U-haul trailer wiring kit that stole trailer power off the vehicle lighting circuits. Didn’t work. Replaced and that didn’t work. Annoyed, and not having a lot of money as a working college student, I designed my own circuit. With 6 diodes, two relays, and two capacitors, all dug out of my scrap electronics bin, I made my own trailer light converter.
Font Rectangle Handwriting Parallel Diagram

Pardon the photo bucket watermark. They changed how many free images you could host, leaving me with too many suddenly, and I couldn’t access the original.

The trick with trailer light converters is you need to stop the brake light from reaching the trailer light so the turn signal can blink, since the trailer light uses the same light for both stop and turn. So just a few diodes wouldn’t work, as the turn would work until you pressed the brake and then it would stop blinking. So the relays cut the brake signal from the side that is blinking. But just a relay wouldn’t work, as it would cut brake signal when the turn signal was on, but as soon as it shut off would shut off and the brake light would turn the light on immediately, keeping it from blinking.

So I threw a capacitor in parallel with the relay. This charges when the turn signal is on, and when the turn signal is off, the capacitor discharges through the relay, keeping it powered. I sized the cap to be big enough to keep the relay energized through the off time of the turn signal. It ended up being able to power the relay for about twice as long as the off time of the turn signal, so the brake light on the side that was previously blinking would turn back on as a brake light approximately 1 second after the turn signal was cancelled, if brakes were still applied.

The 6 diodes kept everything from backfeeding into the other turn or stop circuits.

It worked quite well, and did what it was supposed to do. I towed small utility trailers with basic lights for probably a couple thousand miles with that car and my homemade, electrical taped together converter. If I was to make this now, I’d use a dedicated power wire so the trailer lights didn’t pull power from the vehicle wiring, and use logic circuits and a couple MOSFETs instead of a bunch of diodes, relays, and capacitors. In short, it would be exactly what my Tekonsha trailer wiring harness that I installed on my 2014 does. But I’m in a position now where spending $70 on a pre-made quality harness makes way more sense than making it myself.

But it does show what a few vary basic electronic components can do for you.
 

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I don't think it will be a good idea because during daytime, you will not really notice the parking light because they are only 5 watts and they are not LED. You should be able to tap it from the 3rd brake light in tailgate section to fish your wire. But the idea to turn on the parking light in the tailgate IMO is not worth it when you factor the time and work you would do.
 
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