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Brakes kill power

Discussion in 'Fisher Engineering Discussion' started by shoprat, Dec 3, 2008.

  1. shoprat

    shoprat Junior Member
    from montana
    Messages: 5

    This is my first post here on the board, and I would appreciate
    of any information on troubleshooting the electrics on this

    I purchased this fall a new Fisher HD7'6" and mounted it on a
    full sized '91 blazer.

    I did the install myself.. This Fisher looks to be well designed/made.
    It went on its first run last night and plowed a 1/4 of driveway.

    The install went pretty straightforward and everything
    works fine with one exception. The unit looses power
    with the brake pedel depressed.. I guess I could unhook the
    brake switch and just plow away---but would rather get it
    fully functional...

  2. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    At the risk of stating the obvious, something is definitely wrong with your wiring. Double check your instructions, connection by connection. Try picking up power to the controller from a different source. Does the controller have a ground connection? That may be part of the issue.
  3. stillen

    stillen Senior Member
    Messages: 247

    can you tell me if the truck loses voltage when the plow is NOT hooked up? If so how much, the blazers of that era had a voltage gauge not an idiot light..... I'm just curious to see if your alternator/voltage regulator is on the line of going kaput....... If yoy rev the engine a bit (keep the rpms up a bit) and you step on the brake does the symptons still happen..... Also check the voltage across the power plug for the plow. With engine running you should see about 14.4v....
  4. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,525

    Where did u get power to ur controller?
  5. shoprat

    shoprat Junior Member
    from montana
    Messages: 5

    Thanks for the replies, to clarify the problem a bit more---
    The plow unit works perfectly when the vehicle key is
    in the on position It loses power to the plow unit when
    the brake peddle is depressed and comes back on
    when the peddle is released. Something is back feeding
    through the brake wires..

    Unit is powered via battery exactly as instructions
    show. I ordered this through a dealer and the wiring
    is specific to this vehicle ie headlights.. AH--maybe the power
    to the handheld unit needs to come from a different source.....
    I think I might haved tapped into the trailer brake controler....
    it was close and easy....
    ... Shoprat
  6. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    Let us know if you get it. That's a solid front axle Blazer? That should be an awesome driveway machine.
  7. beatle78

    beatle78 Senior Member
    Messages: 175

    hmmmm.... if you are using a fishstik, there is a ground wire that needs to be wired from the solenoid to the NEG port on the battery.

    See attached pic.

    It seems like something is cause a voltage drop when you step on the brake.

    I'm guessing it's the controller that losing power not the plow itself since the plow power through the solenoid is coming right form the battery.

    If that pic doesn't solve your problem, can you quickly try another power source other then the trailer brake wiring?

  8. shoprat

    shoprat Junior Member
    from montana
    Messages: 5

    Thanks to all for the helpfull info, problem solved. I picked the wrong wire to
    power up the controler..

    The red wire on the fishstick
    I had hooked to a wire that I believe went to a factory brake controller connector..
    I checked it with a test light and pushed on the brake pedel and it goes
    out, anyway found a hot wire in a bundle, no idea what it's for but all is
    good now.. Ready to plow some snow now.. In 4 low it worked

    2cor517-- yep it's an older style blazer with I believe a dana44 axle, off road package
    w/ quad shocks up front. If I used it for more than my own use I might add a leaf and get some
    HD shocks but I only have a 1/4 mile of driveway to do so it should be fine. I just need to build
    a box for some ballast and I'm good to go. Shoprat