Depthfinder wiring ?

Discussion in 'Bubba's Outboards' started by Fishking, Feb 23, 2006.

  1. Fishking

    Fishking Member

    Messages:
    306
    State:
    KC, MO
    Name:
    Andrew
    I have installed a new depthfinder on my boat. The power cable to the DF has two wires, red and black. I have the red wire spliced into the main indash power source from the battery. But where do I need to run the neg(ground) wire to? Thanks for any help.
     
  2. dinkbuster1

    dinkbuster1 New Member

    Messages:
    2,272
    State:
    Ohio
    a ground:D should be a black wire near the power wire. just tap into it.
     

  3. Doctor

    Doctor Member

    Messages:
    378
    State:
    Springfield, Ohio
    FishKing,

    If I were you I would run leads back to your main starting battery for both the power and the negative, and put a fuse right at the battery for the power lead, with you tieing into the main power buss bar on the boat you may pick-up a lot of noise or interference from the main bar.

    This is the way I have done it for years and have never had a problem, noise will do a number on those depth finders, I use Beldon shielded cable back to the the battery and with that fuse right at the battery if something goes wrong it will trip and the power is down.

    Tying directly into the battery will allow you to moniter your voltages from your starting battery and you will be able to see if the battery is getting a charge from the engine.............Doc
     
  4. Fishking

    Fishking Member

    Messages:
    306
    State:
    KC, MO
    Name:
    Andrew
    I should have gave a more detailed description. I have a seperate power wire coming from the battery to the dash of the boat. This wire feeds 3 things. 1. a power point plug in 2. the depth finder 3. the switch to turn on the lights.
    I have a fuse on this wire at the battery, then it runs to the dash where the power plugin is tapped into it. 6 inches further the depthfinder taps into it, then it finally ends up connecting to a postive terminal on the light switch. I have always been able to monitor the battery voltage and have never picked up any kind of noise interference.

    The funny part is that Im installing the exact same depthfinder as I had before. And installing it exactly the way it was set up by the dealer when I purchased it. The black negative wire from the depthfinder has never been connected to anything. I have always seen it just loose under the dash. And the old DF has worked for 5 years (how is this possible?).

    The only negative connection on the battery is the one for the motor. Is there a way this runs back up to the dash someway were you can tie into there? Thanks for any help again :)
     
  5. Nobody Special

    Nobody Special New Member

    Messages:
    614
    State:
    TN
    You have a negative wire for your lights and the power plug. Tap your neg from the depthfinder into that wire.
     
  6. Fishking

    Fishking Member

    Messages:
    306
    State:
    KC, MO
    Name:
    Andrew
    Well, after talking to a couple service centers. They have said that there is noway the depth finder would work without having the negative wire hooked up. This all makes perfect sense, but how in the world would the old DF work? Would the negative wire touching the aluminum dash be an effective ground? This is the only way I can see it happening. This is gettin strange :)
     
  7. Nobody Special

    Nobody Special New Member

    Messages:
    614
    State:
    TN
    If your boat is aluminum, someone probably had the ground wire stuck under the edge of a mountaing screw to ground it and it came loose when you were digging around under the dash. It had to be connected to something for the depthfinder to work. Using the boat hull as a ground is not a good idea.
     
  8. metalman

    metalman Well-Known Member

    Messages:
    3,447
    State:
    IN
    Name:
    Winston
    Grumpy is right in what he say but I would add that not only is using the boat as a ground not a good idea, it's a very bad idea. Galvanic corrosion and all that science stuff.
    You should not think about how the old sonar worked without a ground, it must have had one. Just make sure you hook the new one up as described and you will be in good shape...W