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Need help.Battery isolator in a 2005 chevy

Discussion in 'Truck & Equipment Repair' started by BayviewLawn, Feb 12, 2006.

  1. BayviewLawn

    BayviewLawn Member
    Messages: 67

    Hey,First off im assuming the factory trailer package in my 2005 chevy pickup does not include a positve wire to charge the battery in a trailer im towing.Thats question number one.
    Secondly ,if i need a battery isolater,what amp do i need.dOES THE AMPS OF THE ISOLATER NEED TO MATCH THE OUTPUT OF THE ALTERNATOR OR THE DRAW THE TRAILER MAY HAVE?
    Oops...sorry bout the cap lock button.:dizzy:

    Anyway any help is appreciated
    Tim
    p.s. 44 here on wednesday while 75 miles from here got 18 inches of snow!
     
  2. SnoFarmer

    SnoFarmer PlowSite Fanatic
    from N,E. MN
    Messages: 8,542

    what is the isolator for??

    Duh :dizzy: the trailer brakes

    There should be a hot, wire for the trailer brake battery.
    Ues a volt metter or a test light to find the right lead.
     
    Last edited: Feb 12, 2006
  3. BayviewLawn

    BayviewLawn Member
    Messages: 67

    Theres a hot wire for the trailer brakes,to turn on the brakes when you hit the pedal providing you have a brake controller.But im talking about a wire to charge the battery in the trailer your towing.
    The isolater connects to the alternator and then sends the correct amount of current to the truck and trailer battery depending on each's needs.
    i dont think the checvy has THAT built in it.
     
  4. SnoFarmer

    SnoFarmer PlowSite Fanatic
    from N,E. MN
    Messages: 8,542

    Your right, for that you will need an isolator..
    There easy to install. It will keep the primary battery charged and it will not let the AUX battery discharge the main battery. The only time an isolator was offered was with some camper packages.
     
  5. BayviewLawn

    BayviewLawn Member
    Messages: 67

    Ok so i now know i definatley dont have anything like that from the factory.
    But question 2,the isolators are rated in amps.How do i determine the correct one to get?
    Does it have to match the alternator amps or just be big enough to handle the draw from the trailer?
     
  6. sonjaab

    sonjaab PlowSite.com Addict
    Messages: 1,425

  7. justme-

    justme- 2000 Club Member
    Messages: 2,138

    If you have trailer tow option you have a 7 pin trailer connector right? The center pin should be 12V positive direct from the truck battery or alternator factory. It was in the last Chevy my family bought. The trailer should have the isolater- not the truck.
    If you're only concern is the battery for the surge brakes you don't need an isolater. The isolater is for the trailer use battery- electric lights, TV, stove, etc in a camp trailer.

    The surge brakes only draw battery power when they are activated- as in when the little steel safety cable is pulled, which is only pulled when the trailer breaks away from the tow vehicle in an emergency- in which case the trailer plug with the lights and power feed will disconnect pretty quick I think, if not the minor draw will be of little concern until you stop the truck..., you know, emergency and all :>

    The only draw from that battery will be the natural discharge of the battery, minimal at most. BTW it should be a deep cycle batt for the surge brakes, and it should have a diode already installed to prevent it from discharging the truck instead of charging the battery.
     
  8. NEPSJay

    NEPSJay Senior Member
    Messages: 270

    JUST ME is right.....center pin is 12v constant power
     
  9. sonjaab

    sonjaab PlowSite.com Addict
    Messages: 1,425

    GUYS............BEFORE you say the CENTER lug is 12v constant
    power check out the Marks RV link I posted above.
    It shows lug #4 black is the power source NOT the center lug !

    Also note GM changed the lug arrangement in 2003?............

    BE SURE...use a test light !!!!!!................geo:cry:
     
  10. BayviewLawn

    BayviewLawn Member
    Messages: 67

    I have 5 different trailers with electric brakes(surge brakes dont use a battery) and batterys on them and none of them have isolators on them.Iv had isolators on 2 other vehicles to charge the trailer battery but i dont remember how i determined what amp i needed.
    And all 7 pin trailer wiring is universal.The center pin is not hot.the link provided above is correct.

    Thanks for the help guys.Ill try calling Surpower.they make isolators.

    Tim
     
  11. justme-

    justme- 2000 Club Member
    Messages: 2,138

    I will agree check with a light- Pretty bad when they start messing with the standard wiring codes.....

    You really don't need an isolater.......
     
    Last edited: Feb 14, 2006