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Circuit to separate turn/brake lights.

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=138781
Printed Date: April 29, 2024 at 12:45 PM


Topic: Circuit to separate turn/brake lights.

Posted By: blacklion62
Subject: Circuit to separate turn/brake lights.
Date Posted: April 07, 2015 at 11:49 PM

Hello all.

I have an 88 GMC Suburban. I have euro taillights, and I want to use orange bulbs for the turn signal, in the space where the backup lights are (I have separate backups). The only way i can think of to accomplish this is to come off the turn signal indicator circuit with a relay, and run that to the separate bulbs in the back, one for each side. Will this work, OR, is there another circuit to so this?

Any help is appreciated.

Thank you, James ( The Black Lion) - New user, (so far)!



Replies:

Posted By: Phreak480
Date Posted: April 08, 2015 at 7:58 AM
you could use something like this https://www.etrailer.com/p-118158.html

it splits the 2 signals apart to feed independent lamps. it is commonly used for trailer wiring hookups.




Posted By: davep.
Date Posted: April 08, 2015 at 9:21 PM
blacklion62 wrote:

The way i can think of to accomplish this is to come off the turn signal indicator circuit with a relay, and run that to the separate bulbs in the back, one for each side.


While the above will work (no relays required), the red brake lights will flash with the turn signal ambers. This isn't legal in the U.S. If you have rear amber turn signals, the reds must burn solid as brake lights only. So you need to address this as well, and provide a brake-only circuit to the rear red brake lights.

Here are two ways to do it. The second one leaves the trailer towing connector working as it does now. (It is a Suburban, you probably tow with it). I prefer the 2nd choice.

Choice #1:
At the turn signal switch at the base of the steering column, there is a long connector with about 7-10 wires in it. On the car-side of the connector remove or cut the white wire going to the switch. (You no longer want the brake lights going into the turn signal switch). Attach a new wire to the car-side of the white wire, and run it to the brake lights in the rear.

At the rear, the yellow wire is the Left Turn, and the green wire is the Right Turn. You will have to cut these wires, and splice them to your ambers in the back-up lights position. Then splice your new wire to the brake bulbs yellow (left) and green (right).

Choice #2:
Now I'll complicate this. IF you have trailer wiring, and tow trailers with flat-4 plugs, the above mods will require a trailer adapter to work with the new configuration. OR you can do this:

Leave all wiring intact at the turn signal switch. (Don't cut the white).
Run three new wires to the rear lamp sockets, tied into the following wires at the turn signal switch:

Light Blue = Left Turn
Dark Blue = Right Turn.
White      = Brake Lights.

Leave the trailer connections at the rear the way they are, no changes should be required.
Yellow = Trailer Left Turn & Brake
Green = Trailer Right Turn & Brake.

This is probably the best, cheapest, and most reliable way to do it. Only some 16 Ga wire required.





Posted By: blacklion62
Date Posted: April 08, 2015 at 11:39 PM
Never thought about trailer hookup. Awesome idea, and the cheaper the better!!

James





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