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Brake light wiring with 3 wire turn signal help.

Discussion in 'The Hokey Ass Message Board' started by The Rabid Whippet, Jun 1, 2012.

  1. The Rabid Whippet
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    The Rabid Whippet Member

    Anyone have a wiring diagram how you can make a 3 wire turn signal and brake light switch work? I have the Easy wire kit and everything works except the brake lights. Since the turn signal uses the same filament as the brake, how can I wire it up so the brakes work and the flasher works on the blinker at the same time?
  2. 1971BB427
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    1971BB427 Member

  3. JohnEvans
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    JohnEvans Member

    You need a a 6-7 wire switch or add seperate bulbs for either stop or turn.
  4. tommy
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    tommy Member

    I just add dedicated turn signal lights for the rear as John says. It gives me an excuse to add some cool early lights. I can't stand motorcycle lights but an earl turn signal switch deserves some early lights to make it work.

    [​IMG]

    These are mine that I believe are actually cowl lights with painted bulbs.
    Last edited: Jun 1, 2012
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  5. Lobucrod
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    Lobucrod
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    If you have a 3 wire turn signal switch then you will need separate turn signals and brake lights but it can be done with some relays.
  6. mschiffel
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    mschiffel Member

    I wired both brake lights together and the third brake light on its own dedicated circuit....no problems whatsoever !
  7. bobj49f2
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    bobj49f2 Member

    If you're using a aftermarket switch it's easy. Just tap into the wire after the brake light and before your flasher relay:

    [​IMG]
  8. tb33anda3rd
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    tb33anda3rd Member
    1. Connecticut HAMB'ers

    cool diagram, but that is not a three wire switch.
  9. The Rabid Whippet
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    The Rabid Whippet Member

    I have a 7 wire but I can't stand the cheap chinese crap out there. I figured that the 3 wire with the auto cancelling wheel was cool. And I'm sure not going to run two extra lights on a 1936 Ford coupe. Looks like the cheap 7 wire chinese crap will do for now as I want to get cruising!!!!! The brake lights are the only thing holding me from driving my car.
    And thanks for that diagram, it will help.
  10. tb33anda3rd
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    there are cool old 7 wire switches out there. wire it with plug connectors so when you find an old one you can change it.
  11. superchargednailhead
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    superchargednailhead Member

    I run a 3 wire with single bulb taillights. Go to the auto parts store they make adapter you use for trailers works perfect about 20 bucks.
  12. F&J
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    F&J Member


    Yes, that's what I was thinking. They had made those years ago, back when only the foreign cars had a seperate T/S rear bulb,..... so USA owners could use a normal wired trailer.
  13. A Rodder
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    It is called a Tail light converter. Joins stop and tailights together like how a normal domestic old car would be. But when the turn is on and the brake lights are on, that side will flash and not be over ridden by the brake light.

    How does using a single filament bulb in this application work?



    I think the OP can use this converter with success but only with using the standard dual fillament bulb.


    Wire up your switch you have as instructed to do so. Wire your brake lights switch as instructed and the converter will have five inputs, L TURN, R TURN, BRAKE LIGHTS, TAIL LIGHTS, GROUND. Runs your wires into the converter and coming out of the converter will be four wires. L Turn/Brake , R Turn/Brake, Tail lights, Ground.

    At this point run your wires to the rear lights. At this point you can't run the wires to the front turn signals as they will light up when you brake.

    IF you want to run front turn signals, splice into the left and right turn outputs of your switch and wire forward to turn signals before you connect to the converter. You may or may not have to put in a diode after your splice to prevent back feeding from the converter.


    Does this make sense?
  14. superchargednailhead
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    superchargednailhead Member

    You can't use single filament bulbs. What are you running for taillights the other option would be to add a bulb to your taillight if you could fit it.
  15. RICH B
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    RICH B
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    1. Bengels Hot Rod Seat Frames

    It is very simple to use your three wire signal switch to control four (5) pin Bosch type relays and achieve what you want. One pair to switch between turn signal and brake light function on the rear lights and the other pair to either operate the front signals if you have dual element bulbs, or to switch between park lights and signals if you have single element
    front lights.

    It has been my experience that the "trailer converters" do not hold up in day-to-day service.

    We tried to use them when mounting U.S. wired bodies to foreign cab/chassis when they first started to show up in the market.
  16. A Rodder
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    Gotcha, I miss read and took single bulb, for single filament. I always measure twice, I should just read twice:D
  17. A Rodder
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    It has been my experience that the "trailer converters" do not hold up in day-to-day service.



    I own a trailer hitch shop and have been doing it for years. Your statement holds water. I have had the best luck with the Drawtite 119130 part number the best.

    I pay about 17 dollars for them, while I can get some below ten dollars they just suck. As long as there are no shorts in the wiring after the converter the drawtite ones seem to last several years. But if you have any bare wires or shorts downstream of the converter it will fry it immediately and lose that circuit.

    I have often wondered how the "factory OEM" turn signal switches seem to last decades in cars and trucks, but the aftermarked converter, which basically does the same thing, is quite a bit more fragile.
  18. 3quarter32
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    3quarter32 Member

    I just put diodes in the brake light wires to stop backfeed thru the turn lights. Works fine.
    Lee
  19. A Rodder
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    While this prevents the back feed so both blinkers don't go at the same time,
    I believe this will only work when your blinker is on or brake lights are on, but not at the same time. Your blinker wont blink if you step on the brake. The solid signal from the stoplight switch overrides the flash of the signal.

    Correct?
  20. RICH B
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    RICH B
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    1. Bengels Hot Rod Seat Frames

    Drew up a couple of quick schematics for using 5 pin relays with an old time
    three wire signal switch. One if you have double contact front park/signal lights and one for single contact front park lights.

    If you have a pilot light in your signal switch, you could use a 3 prong flasher or
    combine the the left and right front outputs through diodes to light it.

    Attached Files:

  21. madmike8
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    madmike8 Member

    Thanks.
  22. A Rodder
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    Rich, with the schematic you have, when stepping on the brake and then introducing a turn signal, does it "know" to let it flash even when the brake is depressed? This assuming the turn and brake light wire is the same going to the bulb.
  23. RICH B
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    1. Bengels Hot Rod Seat Frames

    Yes, when either the left or right rear light relay is activated by the turn signal switch, the relay "shuts off" the brake light switch output and "turns on" the signal flasher output to
    the light on selected side.

    The relays are only activated during turn signal operation and are passive otherwise.

    Terminals 30 and 87A are connected when the relays are passive.

    Terminals 30 and 87 are connected when the relay is activated.
  24. The Rabid Whippet
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    The Rabid Whippet Member

    Thanks for the schematic. I will be using this in the future but as my 1936 sits, everything is working with the 6/7 wire turn signal switch. All I need to do now is mount the brake lever switch . I have the wires already run. Woooooh Hooooooo!!! I also ordered some new gauges that have the vintage look. They will be set back under the dash so as not to take away the look of the stock 1936 dash gauges. The ones I bought are really cheap Equis gauges and they suck!!!. It was 65 degrees in my shop and the mechanical temp gauge was reading 145 degrees!!!!!! So I am replacing them all. No more cheap gauges for me!!!.
  25. A Rodder
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    This is great info. I believe the failure rate of this setup, while may be a little more time consuming to wire, will be much less than the converter idea.

    Excellent info.
  26. d2_willys
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    d2_willys Member

    There is a member that has a 2 relay (dpdt type) circuit that does what you want. Just do a search on turn signals.
  27. d2_willys
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    d2_willys Member

    Most of the trailer converters fail due to excessive moisture infiltration. If you mount the converter in the car, the failure rate will be very low. (Take it from me, I work for a converter company.)
  28. RICH B
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    RICH B
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    1. Bengels Hot Rod Seat Frames

    Here are a couple of schematics that were originally posted by HemiRambler and Bloodyjack that use the DPDT relays (from Radio Shack or similar
    vendors) mentioned.

    Attached Files:

  29. LesIsMore
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    LesIsMore Member

    I used the third brake light as the main (I have a single taillight) and have to turn signals
  30. d2_willys
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    d2_willys Member

    Most Excellent Adventure! EXCELLENT!

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