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Four Brake lights and turn signals

sperry

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From what I saw in your diode wiring print, that's what I thought it would do.

`Just didn't want to make that comment until it was confirmed.. >:D

 

DamonCollins

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Thats not what happens on a trailer... if you have turn signal on it blinks...if you press brake while turn signal is on...it still blinks, but the other side brake light comes on.
This is all considering you cut the original wires in tail light bucket.
Thanks,
Damon
 

sperry

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That's right! And why I tap the trailer wiring to provide that operation for my lower lamps on the Av.

Just a preference...
 

sperry

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And of course, I maintain a (F) terminal on the original source wire for whatever reason I need to hook it up again.

Covered from the elements of course, like the other's.
 

DamonCollins

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So, you just modded the lower bulbs by cutting the original and powering from the trailer harness... no diodes?
 

rxzruby

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so your telling me that when i step on the brake pedal only 2 of my tailights are coming on? :7:

Rxzruby
:B:
 

DamonCollins

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Right...the top 2
 

sperry

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Damon, yes. no diodes.

And stock, yes top only are brakes. The lower only are turn.

That no doubt was why JHC did his diode write-up, and me enough to do the source rewire for the lower ones. I left the top unchanged.

So, whichever way you chose....
 

ginman

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Thanks to JHC for the idea on this one.

I saw this done on Hangman's truck at his house, and liked it.

The one thing that bothered me is the extra current load put on the trailer lights to run the turns/brake (9A extra current).
I tow a boat, run sail panel leds, and a line of fire off of the turn signals on the trailer harness already, so pulling more current was not a good idea. Also, cutting the existing wires and running from the trailer harness was not an option, if I blow the trailer fuse in salt water, I don't want to loose my brakes/turns.

So, I modified the diagram to use relays to keep using the brake/turn signal power, but trigger the crossover between the two with the relay triggered by the trailer wires. The relay only draws 30mA off the trailer wires to run the coil, so no big current drain.

This circuit works exactly as the JHC diode version. When you hit brakes only, all 4 tail lights go on. When you hit directional only the 2 lights on the directional side will flash. When you hit the brakes and the directional, 3 lights will be on solid and the lower one on the directional side will flash.

I used 2 radio shack 275-248 12vdc coil,10A @ 24VDC relay, and 2 packs (4 total) 276-1661 diodes.
The diagram shows the pin numbers to use on a standard 12V automotive relay.
 

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ginman

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All 4 brakes on pic
 

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sperry

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OK,

I modded mine with the trailer source - raw. The relay idea is a good call, but the salt water must be the fuseblower? The load is ok unless you have more than three turn/brake lights each side of your trailer. (Unless they're LED's w/o load resistors accross them). The top brake lights would still operate but you may lose turn if the (trailer) fuse(s) popped.

I rarely tow a trailer myself..

Each lamp is normally 1A for tail ?Amp for marker and 3Amps for Brake/Turn (Your mileage may vary.. >:D)
 

Billy3sticks

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Ginman said:
Thanks to JHC for the idea on this one.

I saw this done on Hangman's truck at his house, and liked it.


I really do Love this mod....

When the guys id it for me at my Beast Feast, I couldn't beleive it.

What a difference it makes, especailly at night.

Thanks again to the FL. boys who made this happen.... :love:


Hangman
 

ginman

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sperry said:
The relay idea is a good call, but the salt water must be the fuseblower?
My boat trailer does have 4 brake turn lights, one on the trailer frame and one set on the guide poles up high, so the load would be too close for me to be comfortable.
I really don't have an issue with the trailer fuse blowing now, but my bulbs do get shattered by the hot/cold of putting them in water, saltwater is a pretty good conductor, so, I didn't want to rely on the trailer harness to power my truck lights, just in case the trailer fuse goes.
In the diagram above, the normal turn/brakes in the truck are still isolated from the trailer circuit. Even if the relay fails, or trailer fuse blows, the truck tail lights will simply revert back to normal operation.
Just the way I choose to do it.

 

Steamer

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Working on several mods today on my new AV I picked up yesterday. This A4B one has me hooked and I really appreciate the time some of you fellas put in to get this info out.

My newb question for a less than average eletrician: 1) After purchasing and looking at the diodes, I assume that you splice the wire and insert the diode into each open end and then tape it up. White faces the brake lite.....correct?

One other question: 2) Any particular LOF is better than others, or can I get the $55 one over the $100 one and be OK? Suggestions and links or names of LOF manufacs.

Thanks in advance

Steamer
 

ginman

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Steamer,

You are correct about cutting the turn signal wires and inserting the diodes.  That will prevent feedback.

The Altec LOF ($100) is better quality (now, they had issues with older ones) than the Toucan/Eurolite($50) version.  I have heard of people having problems with the $50 one.  I don't know yet if they have corrected it.  I seam to remember someone here saying it caught fire and melted. The Canadian folks had a group by at one time on the $50 ones, as they couldn't easily get the Altec ones.  With my LOF, made sure to seal up the conector end with some silcone to prevent water intrusion, just safety.  Mines been good for about 8 months now.  Buy from a good dealer in case of breakage in shipping is my advice.
 

scoupe

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Some drawings, since a photo can't capture all the features of this mod, for those that need to visualize the mod.

(I think I captured the effect - only showed left turn, right would be similar, and took a guess on 4-Way operation)

Ginman -? With the relay - do you see a slight delay in lighting top to bottom?? I'd guess it might only be noticeable with LED lamp, not incandescent.
 

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SamHouseIII

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Completed this today, Great MOD, Cost me about a dollar over here. Thanks for it.

SFC House
 

TRzAV

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sperry said:
OK,

I modded mine with the trailer source - raw. The relay idea is a good call, but the salt water must be the fuseblower? The load is ok unless you have more than three turn/brake lights each side of your trailer. (Unless they're LED's w/o load resistors accross them). The top brake lights would still operate but you may lose turn if the (trailer) fuse(s) popped.

I rarely tow a trailer myself..

Each lamp is normally 1A for tail ?Amp for marker and 3Amps for Brake/Turn (Your mileage may vary.. >:D)

Hey - Sperry or anyone else who knows what I should do,

I did the traditional 4-way brake mod with the diodes to trailer harness and I'm having trouble with my trailer lights when hooked up.  There is a serious delay, if my turn signals even blink, when I brake and use my turn signals.  You had mentioned LED lights w/o load resistors; where you talking about the trailer's lights or the AVs brake/turn lights?  If you were talking about the trailer, would it go back to normal if my trailer had the LEDs brake/turn lights?,

Any help would be greatly appreciated,  (y)
Troy
 

holstbnet

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Two questions:

1) Does anyone know why GM setup the rear lamps this way to begin with? The stock configuration doesn't make sense. The Trailblazer is like this too, only that one REALLY bugs me because the turn signal is BIGGER than the brake lamp there!!

2) Does the Export version of the Avalanche have amber turn signals? Now THAT would be a cool mod, just to be different in the states. And, that's one reason I could see for having the stock configuration instead of All 4 on brake.
 

SamHouseIII

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holstbnet,

In Germany they remove the Back up light bulbs, Replace with Amber and relocate a 1 or 2 back up lights to rear bumber.

Sam
 

ginman

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TRz66 said:
sperry said:
OK,

I modded mine with the trailer source - raw. The relay idea is a good call, but the salt water must be the fuseblower? The load is ok unless you have more than three turn/brake lights each side of your trailer. (Unless they're LED's w/o load resistors accross them). The top brake lights would still operate but you may lose turn if the (trailer) fuse(s) popped.

I rarely tow a trailer myself..

Each lamp is normally 1A for tail ?Amp for marker and 3Amps for Brake/Turn (Your mileage may vary.. >:D)

Hey - Sperry or anyone else who knows what I should do,

I did the traditional 4-way brake mod with the diodes to trailer harness and I'm having trouble with my trailer lights when hooked up.  There is a serious delay, if my turn signals even blink, when I brake and use my turn signals.  You had mentioned LED lights w/o load resistors; where you talking about the trailer's lights or the AVs brake/turn lights?  If you were talking about the trailer, would it go back to normal if my trailer had the LEDs brake/turn lights?,

Any help would be greatly appreciated,  (y)
Troy

TrZ66,
I assume the modification works perfectly fine for the truck lights without the trailer hooked up.  Is it possible you used small ampere diodes?  1Amp-3Amp.  It is possible the large current draw from the trailer lamps are reverse biasing the diode between the Brake and Turn wires, allowing current to flow from the brake wires into the trailer harness, overriding the turn signal flash signal.  Perhaps try a larger 6amp diode in between the brake and turn wires.  Or you can get relays and do as I did to isolate the trailer harness from the brake/turn wiring of the truck. This way all truck wiring maintains more normal current load levels, especially when hooking up a trailer.
All four brake/turn with relay.
My guess anyway, hope it works out for you.
 

sperry

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If a diode is not conducting (or is a dead short with lamp current), it simply won't heat up. Some have installed 1A diodes and ran the brake/turn filament current through them (3A) and they work. But if you're waiting at a light or creeping in traffic, the brake lights, depending if they're wired that way, will draw the 3A for a duration that could overheat and short the smaller diode (more likely than it opening up inside). Now you have a piece of wire instead and no more isolation. 2.1 Watts is just too much for those little diodes to dissipate!

3A diodes should be enough, but personally, I would use a 6A, for the small change more in price.

So, if weird things are going on shortly after you finished your project, I would check that.

I hadn't checked the affect of flasher & turn loading of LED's on the trailer circuit, however, since there is a variety of the total number of lamps (1 to 3) that each side can handle of the incandescent type. That, without a considerable variation of flasher rate, I would doubt that the lighter LED load would change.

It likely would on the vehicle's regular turn sig wiring, since the lamp design load isn't normally changed. (Until we mod things on the circuit. >:D)

 
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