80 Z turn signal - intermittent problem

Discussion in 'Troubleshooting & Diagnosis' started by JD Z, Aug 27, 2017.

  1. JD Z

    JD Z Veteran Member

    Turn signals are all working at the moment. I've noticed twice in the past few weeks that the right rear signal was not working and the right brake light was blinking faintly. No orange turn signal blinking, but the red tail light blinking faintly when it happens. Again all working perfectly today.

    Any thoughts on what might be occurring? I'm new to the older car world, so I've got much to learn. I have the wiring diagram from barnfind79 that I haven't printed out yet. Thanks for your words of wisdom. :)
     
  2. Gary S

    Gary S Administrator Lifetime Gold Member

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    Bismarck, North Dakota
    That sounds like a bad ground at the tail light. The power is leaking through the ground and causing the wrong bulb to flash.
     
  3. JD Z

    JD Z Veteran Member

    Sounds favorable. If it acts up again, should I check and clean all bulb connections on the left rear? Or is there a specific ground to check?
     
  4. JD Z

    JD Z Veteran Member

    More findings on the signals. The backup bulbs were bad and now replaced. Still the same issue, but I've narrowed in on what they are doing. Tests of various situations reveal the following:

    (Lights ON, reverse lights OFF) - right signal blinks dim along with tail light blinking dim and corner light blinking dim

    (Lights ON, reverse lights ON) - right signal solid very dim, tail light dim and no corner light…reverse light dim

    (Lights OFF, reverse lights OFF) - right signal blinks ok with tail light off and corner light off

    (Lights OFF, reverse lights ON) - SLOW blink…right signal blinks very dim with tail light blinking dim and corner light dim…reverse light blinking

    So the question is, what points in the car should I check as far as ground issues? Or any other suggestions would be welcome.
     
  5. JD Z

    JD Z Veteran Member

    Looking for where to check grounding issues on turn signals. Looking at the rear lights, I don't see anywhere grounding issues would be in the wires. The sockets were full of gunk, like from the factory it looks. I cleaned the bulb sockets out on the bulbs I replaced. Would potentially I need to clean out all of the rear light sockets? Are there other ground connection points such as under the dash? I'm only having problems with the right rear, all other lights/signals work as expected.
     
  6. Gary S

    Gary S Administrator Lifetime Gold Member

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    This wiring diagram
    http://www.nastyz28.com/camaro/wire/78w-rear.jpg
    shows a body ground somewhere in the rear of the car. The black wires for each light tie to this ground as shown. All connections between the black wires need to be secure if the lights are to work properly.
     
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  7. JD Z

    JD Z Veteran Member

    Gary, on the diagram, is the black dot where the black wires meet supposed to be a ground point to the body, or just a connection point for the wires? Should I track back from the lights to a point of connection to the body for ground?
     
  8. Gary S

    Gary S Administrator Lifetime Gold Member

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    Apr 14, 1999
    Bismarck, North Dakota
    The bladk dots are tie points where multiple wires come together. The ground is on one of those tie points with a "ground symbol". Just where that might be located I can't say because I don't have an 80 to look at.
     
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  9. JD Z

    JD Z Veteran Member

    The turn signal sockets have a bunch of gray waxy goop in them. Seems it would be hit and miss to get a good connection. This goop appears to be a factory step that had some purpose...there is a ton of it in each socket. On two of the sockets that I replaced bulbs, I scraped it out with a small screw driver, but didn't spend much time doing it. I need to figure out the best way to remove this goop and get those sockets clean. I'll play more tonight, but thinking through my best options for cleaning the sockets. There is no rust in them which is good.
     
  10. Gary S

    Gary S Administrator Lifetime Gold Member

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    Apr 14, 1999
    Bismarck, North Dakota
    The goop in the sockets is grease the factory put there to prevent moisture from getting into the sockets and causing corrosion. By the time a vehicle reaches this age, the grease is dried out and no longer able to keep things water free.
     

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