Announcement

Collapse
No announcement yet.

New battery, no start?

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    New battery, no start?

    This is a repost of my thread in the Electrical forum for visibility.

    Ok, I recently got a new battery because my old one wasn't holding a charge... With the new battery, my car still doesn't want to start. I'm getting 9.5-9.8V with ignition on, engine off, and the starter just won't turn. If I jump it, it will start, but it seems slow. I'm just looking for what the culprit might be, and what I need to fix/replace.
    TIA
    If life passes you by... Downshift.
    Tags: None
    #2
    Where are you measuring that voltage? It is way too low for system voltage with a fully charged battery (should be 12.7v).

    That low a system voltage implies a bad connection somewhere. Start at the battery and work forward through the power distribution system until you find the point where the voltage drops. The problem will then be between that point and the previous good measurement.
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment

      #3
      sounds like loose/corroded connections to me

      I agree with JLevie, voltage accros the battery should be at least 12.5v with no load
      1989 cirrisblau-metallic 325i

      Comment

        #4
        Its 9.5V with the engine off, around 13 with the engine on. My head unit has a voltage read-out, which I don't entirely trust, but its proven relatively reliable so far...
        If life passes you by... Downshift.

        Comment

          #5
          just because the battery is new doesn't mean it is good. if you are only getting 9.5v then it's probably bad. have it tested before you pull you hair out looking for bad wires.
          Build thread

          Bimmerlabs

          Comment

            #6
            The low voltage is weird. Here's a problem I once had where my car would not start, which may or may not help you.

            When this happened to me, the positive terminal from the battery was not making good contact with the starter. As a result, the current was arcing from the wire straight to ground via a nearby bolt. This resulted in a short circuit periodically when I tried to start the car, even though the battery was fine. The solution was to clean up the dirt and carbon that built up around the starter terminal. It's worked fine ever since!

            Comment

              #7
              If the battery is good (have it tested) you probably have a drop.

              Check all of your connections both hot and ground.
              I'm Not Right in the Head | Random Rants and other Nonsense1st Order Logic Failure: Association fallacy, this type of fallacy can be expressed as (∃x ∈ S : φ(x)) → (∀x ∈ S : φ(x)), meaning "if there exists any x in the set S so that a property φ is true for x, then for all x in S the property φ must be true".

              Comment

                #8
                Back from the dead.
                Had the Battery tested (group 48), tested out perfecly.

                I've tightened as many connections as I could find.

                What now?
                Thanks
                If life passes you by... Downshift.

                Comment

                  #9
                  Use a meter and follow the main power lead from the battery forward to find the area that is causing the voltage drop.
                  The car makes it possible, but the driver makes it happen.
                  Jim Levie, Huntsville, AL

                  Comment

                  Previous template Next
                  Working...
                  X