Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

How was the factory dual battery wired up?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Pure Insanity, Sep 13, 2002.

  1. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    And yes I am talking a gas motor. My Blazer came set up for duals when I got it, but only had a single running. I would like to get the dual set back up, and already have a battery in the tray. The neg. cable is still there for the 2nd but all the pos. wiring is gone.

    I have read about isolaters and switches on here, but I am curious of how GM set it up.
     
  2. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    They are wired in Parallel. I think factoyr had a double ended cable (the ends looked like a standard GM side post cable). The side post cables will stack and all you need is a longer bolt. Many late 80's Caddies had a stacked cable so they should have the longer bolt if your having problems with the dealer.
    Now fair warning. BOTH batteries must be new. If you put a new batterie in one side and use your old battery they will have a slightly different output. It will cause the Batteries to kill each other.
    I plan to put a second battery in but I'm going to use a Battery selector switch and a dual battery isolator. The isolater will let me chage both battieries but keep them from fighting each other. THe selector will let me run off either battery or gang them together.
    http://www.westmarine.com/webapp/commerce/command/ProductDisplay?prmenbr=201&prrfnbr=7582&store_num=9&store_name=Electrical&subdept_num=462&subdept_name=Meters%20%26%20Distribution&class_num=466&class_name=High%20Amperage%20Distribution&outlet=
    That one is a bit pricy. But it has some stuff you won't need. West is a little high to begin with any way. THere is a less expensive one available for about $50. West even carries it in their stores but it's not on thier web site.
    http://www.colehersee.com/home1.asp is the manufacture of many of these.
     
  3. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    Thanx for the info and links Grimmy. I knew there had to be a reason people were running the isolators and switches but never knew why.

    Both batteries are fairly new, ones an 800 the other is a 1000.
     
  4. Sandman

    Sandman 3/4 ton status Author

    Joined:
    Apr 15, 2002
    Posts:
    5,653
    Likes Received:
    0
    Location:
    Pocatello, ID
    You can use a Ford starting seloniod as a cheap battery switch.
     
  5. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Drop in at the local Chevy dealer and ask them for a battery isolation relay from a late 80's gas engine 3/4-ton pickup wtih the camper special package. Then see if they can show you the wiring diagram for it. /forums/images/icons/cool.gif They had a big relay that went between the batteries. When the key was in the "run" position, the relay would close, connecting the 2 batteries in parallel and letting them both charge from the alternator. When the key was turned off, the relay would open, removing battery number 2 from the main power circuit of the truck. So you could run battery number 2 totally dead without having any effect on the main starting battery. It's a cheap way to run dual batteries without any fancy wiring, diode-based isolators, etc.
     
  6. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    Thanx guys.

    How do I wire the Ford solenoid?

    I have a good friend thats a GM parts guy so getting the part and viewing the schematics wont be a problem for the GM set up. /forums/images/icons/wink.gif
     
  7. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    I'm not sure that the Ford solenoid is rated for a 100% duty-cycle. It may overheat if left in the "on" position for too long. I thought about using one to control some off-road lights, but in testing, it got way too hot for me to touch in about 2 minutes. /forums/images/icons/shocked.gif And all that was energized was the relay coil. I didn't even have a load attached.
     
  8. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    I didnt think of the duty cycle. Thats a good point.

    Ill check into the GM parts. Im not a big fan of ANYTHING "high tech".
     

Share This Page