Powermaster 8172 alternator

Electrical and Ignition

  1. oldkimmer

    oldkimmer FABO Gold Member FABO Gold Member

    Messages:
    10,453
    Likes Received:
    1292
    Joined:
    Nov 11, 2006
    Location:
    Kindersley, Saskatchewan,
    Local Time:
    9:48 PM
    Hi there, installing a 1 wire alt on my race car. 74 duster factory wiring deleted. E fuel pump, E water pump, E 16 in fan, MSD ign with 7AL box. 2batteries in the trunk. 2 Post kill switch. So if I read the NHRA rule right I run a wire from alt to pos side of kill switch. I want to put a cut off switch of some kind while running the quarter mile then be able to switch it back on after the run. It's a 55 amp alt. So a toggle switch won't do. What do the guys that did this suggest. So my thinking is run wire from alt to switching device then to kill switch. Thanks. Kim
     
  2. 67Dart273

    67Dart273 Well-Known Member

    Messages:
    39,277
    Likes Received:
    6923
    Joined:
    Oct 14, 2010
    Location:
    Idaho
    Local Time:
    7:48 PM
    Kim I don't like that method, because with the battery killed, YOU STILL HAVE a fairly large "welding cable" (sparking and arcing) that is live from one end to' to other. Crackedback takes one approach, mine is to use a "4 post" switch, which nowadays are VERY available. What you do is, if you have EFI, but the small posts in series with your pump relay. If you run a carb, use those terminals to kill a relay feeding the ignition. What that switch is off, wired that way, ALL power is "in the trunk."

    On a side note..........you need a MUCH larger charging wire for a "one wire" system. Perhaps at least no6 and better no4
     
  3. oldkimmer

    oldkimmer FABO Gold Member FABO Gold Member

    Messages:
    10,453
    Likes Received:
    1292
    Joined:
    Nov 11, 2006
    Location:
    Kindersley, Saskatchewan,
    Local Time:
    9:48 PM
    Thanks Del, maybe Rob will chime in. Kim
     
  4. famous bob

    famous bob mopar misfit

    Messages:
    11,804
    Likes Received:
    3066
    Joined:
    Aug 14, 2011
    Location:
    okla
    Local Time:
    9:48 PM
    I have a 130 amp powermaster one wire on my 68 fastback, underneath the motor plate, where the stock fuel pump used to be. I have a # 10 wire to the stock mopar battery connection on the starter relay, which is near where the heater motor used to be. It works fine. #2 welding cable from trunk on same post. battery stays charged, doesn`t run down if left for a few weeks, always around 14.2 on the hand held. starts the 505 even when hot. so far so good.
     
  5. AJ/FormS

    AJ/FormS 68 B'cuda fb, Form S clone ... 367/A833/3.55s FABO Gold Member

    Messages:
    15,435
    Likes Received:
    4489
    Joined:
    Jan 19, 2014
    Location:
    South-Central Manitoba,Canada, 900ftelevation
    Local Time:
    9:48 PM
    I have an idea;
    What if? What if you installed a normally open solenoid in the 1-wire output, and triggered it to close from the ignition sw in run, but ran the solenoid ground side thru a micro sw on the gas-pedal or carb linkage.
    In this way the alt would be working anytime the ig sw is in run, except when at WOT, it cuts out. And it also quits when the master cut-off is engaged cuz the solenoid is normally open.Just an idea I once had a long time ago. Perhaps nothing new under the sun.lol
     
  6. 67Dart273

    67Dart273 Well-Known Member

    Messages:
    39,277
    Likes Received:
    6923
    Joined:
    Oct 14, 2010
    Location:
    Idaho
    Local Time:
    7:48 PM
    But are you running a lot of load? Like fans? You don't seem to have a very long run of no10, there, probably OK

    The reason "one wire" needs a big charging line is that the sensing is right at the alternator........the load on "the other end" does not get compensated for
     
    • Agree Agree x 1
    • famous bob

      famous bob mopar misfit

      Messages:
      11,804
      Likes Received:
      3066
      Joined:
      Aug 14, 2011
      Location:
      okla
      Local Time:
      9:48 PM
      fuel pump for the fuel inj., MSD, one elec. fan, that comes on quite frequently now that the hi 90-100 degree temps have hit. I did have a smaller wire at first, when I first installed the EZ wiring kit, but had to go to the # 10 to get the battery to stay charged, Have thot about going one size bigger, but all seems well in the charging end of it. so far so good!
       
    1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
      By continuing to use this site, you are consenting to our use of cookies.