Signal lights stop flashing

Discussion in '1973-1987' started by shannong, May 30, 2011.

  1. shannong

    shannong Member

    Joined:
    May 30, 2011
    Messages:
    2
    I have a 79 Sub. the problem i have is when i have the signal lights on they work and flash fine until i hit the brakes when the brake lights are on the lights stop flashing. It has a trailer brake controler but it doesnt seem to work, I have replaced the flasher and all the bulbs. does anyone know where to look next or have had this problem? I dont understand why they work until i hit the brakes. i am hopeing that someone has already fixed this problem and can point me in the right direction. i am a disabled vet. and getting around and under the dash and truck is hard to do and i can not afford to pay someone to fix it for me. so any advice that point me to somewhere that will save me alot of work and money will be greatly appricated
     
  2. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,643
    Location:
    AMERICA !
    T.S.Failure

    WELCOME ! .

    THANK YOU FOR YOUR SERVICE ! (yes , some of us never forget)

    Anyways , 99 % of the time , this is caused by poor grounding in the rear taillight sockets , go to your FLAPS & purchase a battery cleaning brush and use it to clean the socket until it's shiny clean again then carefully smear a tiny bit of wheel bearing grease on the brass part of the # 1157 taillight bulbs .

    It is very important to use a conductive grease , not dielectric typ of grease some will suggest .

    Once this first step is done , re - test then as necessary , add a grounding strap from one taillight mounting bolt to the body , as needed .

    Take the time to do this correctly in the correct step by step order and it'll never trouble you again .

    I like to spray paint this battery brush red so I'll know forevermore it's a taillight tool and not to ever touch a battery with it .
     
  3. shannong

    shannong Member

    Joined:
    May 30, 2011
    Messages:
    2
    thank you. and thank you for the answer. i will do that and check it out first thing in the am. i pray this solves my problem.
     
  4. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,643
    Location:
    AMERICA !
    Don't Pray !

    We'll do that for you , you're a Veteran .

    Just go buy a good test light , it'll have a pointy end on it and a long thick wire with alligator clip on t'other end , NOT Pep Boys Et Al crap and NO coily cord ! .

    Go to NAPA and buy the expensive one , it'll still be working 25 years later & not pi$$ing you off with false readings like the cheapo ones do .

    Work slowly and carefully , once you get the hang of it , you'll be in big demand to fix all those inop. Hot Rod lights .
     
  5. nerfherder78

    nerfherder78 Member

    Joined:
    Aug 15, 2003
    Messages:
    325
    Location:
    Fairfield, CA
    Did this just start happening or has it been doing it since you've had the truck?

    I'd think one of two things have happened:
    1. The brake controller is incorrectly installed and is causing the problem (I've never messed with a one off these so I'm not sure how they're connected).

    2. The turn signal switch has gone bad.

    The brake switch is behind the two panels under the steering column, on the right side directly in front of your knee as you're sitting. The turn signal switch connector is directly behind and above that, flat against the column. The wire colors I'm getting from my 85, but they should be the same for older trucks as well.

    When the turn signals are off, the wires to the both brake/rear signal lights (dk green and yellow at the ts switch connector) should be in contact with the white wire that runs from the brake switch to the ts switch. The brake switch should have 12V via the orange wire from the fuse box, this is interrupted when the brake pedal is released and pushes the button on the switch.

    When you activate the turn signal, one of the rear signal/brake light wires (dk green = right, yellow = left) will be switched from the brake light switch to the flasher relay (which also has constant 12V from the fuse box).

    I'd be more inclined to believe something is wrong in the ts switch, and both wires are still in contact with the brake switch; but without being there to see it/test it, this is just a guess.
     

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