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lights and turn signals

Discussion in 'Audio, Video & Gadget Tech' started by lowriderinms, Jul 24, 2009.

  1. lowriderinms

    lowriderinms Rockstar

    i have a 95 3500 with the 6.5l turbo.. my new playtoy! anyway here my problem... 1. the dor locks do not work.. fuse looked good.... just nuthing. i have not torn apart the door to check wiring but it will be soon. 2. my running lights work, except for tailgate... but none of my turn signals do, and one 1 of 3 brake lights do. again the fuses looked good. i noticed when i go to use the left dignals.. the dah indicator blinks, but when i go to use the right one.. nothing comes on.. not even the hazrds work...

    Yall i could use a lot of help and info on how to find this problem. it is def a truck that has been tinkered with in the wrong way...

    anything would be greatly appreciated!
  2. 2wheelmudder

    2wheelmudder Rockstar 100 Posts

    so i would check all the light bulbs, on them turn bulbs, they have two seperate filaments, one could be broken, and so i would check all the bulbs, or i would check the wiring that runs to back and stuff like that, cant help with pdl
  3. bill190

    bill190 Rockstar 100 Posts

    You may have a BRAKE and a STOP-HAZ fuse. Check both.

    How to check fuses...
    http://www.dinosaurelectronics.com/Test_Fuse.htm

    Then may want to go ahead and check all fuses. Check one at a time. Remove it. Test it. Replace it and then test the next.

    That is because tracking down the wiring problems can take hours of work, best to be SURE it is not a fuse problem!

    Check your running light tailgate light bulb. See if replacing the bulb fixes that problem.

    Then check the bulbs in your tail lights to be sure the bulbs are OK. Also that they are the correct bulbs. Some bulbs have two filaments in them and would be the correct bulbs. Others take just one filament bulbs. Sometimes people install the wrong bulbs.

    Some auto parts stores have people working there who know what bulbs you should have and are quite helpful with these things. Might try there.

    If the above does not resolve the problems, then you would need a GM Factory Service Manual set which would have completer wiring diagrams. And you would need to know how to troubleshoot electrical problems and know how to use a multimeter. Otherwise take your vehicle to a GM dealer for service.
  4. lowriderinms

    lowriderinms Rockstar

    lights again

    well, got the tallights fixed. the dash indicator does not work, but the exterior does! third brake is out, the whole socket was burnt out and no power on the harness.. the door locks do work now.. so far its ok. the taillight had a bad circuit board... the rest is slowly but surely goin to work...
  5. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    That's the best way to approach it. Clean all the suspect circuits one at a time.
  6. bill190

    bill190 Rockstar 100 Posts

    Good work!

    The dash indicator is probably a burnt out bulb. Pull the instrument cluster and see if you can replace the bulb.

    When I pull an instrument cluster, I like to check all the bulbs. I take a 6 volt lantern battery and use alligator clip test leads and check one bulb at a time. These will dimly light up with 6 volts.

    6 volt lantern battery...

    [​IMG]

    Alligator test leads...

    [​IMG]


    As to the third brake light, try tracing the wire if you can. If you can trace it to wherever it goes and test it from there, that would be good. If it was shorted, it may have burned out the wire somewhere.

    You may be able to go to a wrecking yard with a few tools and find a similar vehicle already mostly torn apart. Then might be able to see where that wire goes. Maybe need to remove a couple more things.

    Otherwise you would need a factory wiring diagram. Wires in vehicles can be impossible to trace because they wrap up a zillion wires in one cable and run the wires in concealed areas. The factory wiring diagram would show where all the wire go.

    Also before going to all that work, might want to run a wire to battery ground and use that as a ground source for testing the wire to the light (using multimeter or whatever). You can place a large brick on the brake pedal to keep the stop lamps on for testing. Also do the opposite. Switch your wire to positive and check the ground to the light.

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