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Hydraulic Brake Light Switch Failure - Again

Discussion in 'Flat Fender Tech' started by CJMark, Feb 18, 2019.

  1. Sep 28, 2019
    colojeepguy

    colojeepguy Colorado Springs

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    Well, scratch the mechanical switch idea. On a V6 Jeep there's no room to get one up in there.
     
  2. Sep 28, 2019
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

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    You have through the floor pedals, right? If so, you could run it off the brake arm under the toe board?

    When i put in swinging pedals, I made sure to get the YJ pedal assembly that had the integral mechanical switch. The Hydraulic pressure switches seem to be a problem on all the vehicles that used them.
     
  3. Sep 28, 2019
    colojeepguy

    colojeepguy Colorado Springs

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    Yep. There's just no room under there.
     
  4. Sep 8, 2020
    teletech

    teletech Member

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    Old thread I know, but just in case someone trips over while troubled by this issue I've attached pics of the switch (which looks like the '76 switch mentioned earlier by Timgr) and bracket that was used in my '67 V6 CJ.
     
    47v6 and Fireball like this.
  5. Sep 11, 2020
    jeeper50

    jeeper50 jeeps 'till I die

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    Don't forget to swap over to LED 1157 bulbs to lessen the amps going thru the switch.
     
  6. Sep 11, 2020
    teletech

    teletech Member

    Santa Cruz, CA
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    It will also help extend the life of the plastic lens, but you might need a different signal flasher, particularly if you also replace the front marker lights.
     
  7. Sep 11, 2020
    OnlyOneDR

    OnlyOneDR Member 2023 Sponsor

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    This is a place where a relay might help. Using the switch to actuate an interposing relay instead of the light circuit directly would drastically cut down on the current being made and interrupted with the switch. That would be something easy to hide under the dash and keep all the stock components.
     
  8. Sep 11, 2020
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Re the relay, maybe. The load from a relay is ca 150 ma, and that's likely less than the brake light filaments. It's also a different load, where an incandescent filament starts as a high load (low cold resistance) and eases off as the lamps light (higher hot resistance). This might be hard on the switch ... maybe. The relay does store some energy in the coil, which means a slow ramp up, and an inductive kick at shut-down. All of this is probably an easier load for the hydraulic switch, but I suspect the main problem is quality and materials of the switch, not the load characteristics.
     
  9. Sep 12, 2020
    OnlyOneDR

    OnlyOneDR Member 2023 Sponsor

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    1157 are ~2A operating (27 watts @ 13-14VDC). LED are about 1/10th of that. I agree it sounds like poor quality switch contacts but if nothing better is available either LED or a relay would be a good workaround.

    My wife's Toyota RAV4 has the same issue; there are two pairs of contacts in the brake switch (one for the lamps, the other for signaling to the ECU for ABS/Traction Control/ELSD) and the main lamp contacts burned up after about 10 years. The new replacement switches only last a few years; the intermittent issue we had with the old switch has already popped up again on the replacement. Not an expensive fix but frustrating nonetheless.
     
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