Aloha! 2005 R53 MCS battery light + dead PS pump

Discussion in 'Starting Line - New Member Introductions' started by BLKmini808, Apr 22, 2015.

  1. BLKmini808

    BLKmini808 New Member

    Apr 22, 2015
    7
    0
    0
    Honolulu
    Ratings:
    +0 / 0 / -0
    #1 BLKmini808, Apr 22, 2015
    Last edited: Apr 25, 2015
    2005 R53 MCS battery light + dead PS pump

    I'm running into the notorious battery light paired with the PS pump being dead and was wondering if anyone could help me understand what y'all did to solve and/or diagnose faults.
     
  2. ZippyNH

    ZippyNH Well-Known Member

    Jan 25, 2010
    1,404
    688
    113
    Pilot
    Southern NH
    Ratings:
    +688 / 0 / -0
    failing alternator will turn on the light, then the ps pump is MADE to shut off...it has a sense wire...not enough alternator voltage, it simply turns off to help you get to your destination before the battery dies....
    first thing i would check is the alternator...
     
  3. BLKmini808

    BLKmini808 New Member

    Apr 22, 2015
    7
    0
    0
    Honolulu
    Ratings:
    +0 / 0 / -0
    Ic, I will check that first but would a failed PS pump also trigger that light?

    Reason why i'm asking is because the alternator is relatively new. (despite knowing these could break any time)
     
  4. MCS02

    MCS02 Moderator
    Staff Member Articles Moderator Supporting Member

    Jul 31, 2009
    11,188
    6,185
    113
    Male
    Ratings:
    +7,911 / 10 / -3
    Check the battery. Take it to a parts store and have them do a load test on it. Minis with a bad battery do all sorts of flaky stuff. Start with the battery.
     
  5. MCS02

    MCS02 Moderator
    Staff Member Articles Moderator Supporting Member

    Jul 31, 2009
    11,188
    6,185
    113
    Male
    Ratings:
    +7,911 / 10 / -3
    More than likely no. My PS started to fail but I had no lights. After you check the battery check the bolt in the bot with the + on it under the hood this is a known problem spot, some times they get lose. Also make sure the battery terminals are clean and tight

    Let us know what you find
     
  6. Dave.0

    Dave.0 Helix & RMW Powered
    Lifetime Supporter

    May 4, 2009
    25,021
    13,497
    113
    Burbs of Philly, PA
    Ratings:
    +14,644 / 10 / -4
    How many miles are on your car? Because this could be many things like bad OEM battery at the end of its life, bad Alternator, bad or going bad OEM crank Pulley, failing PS pump or PS fan.

    Even if the Alternator in new if it is a rebuilt unit or non campatable OEM unit it can and may still fail.
     
  7. BLKmini808

    BLKmini808 New Member

    Apr 22, 2015
    7
    0
    0
    Honolulu
    Ratings:
    +0 / 0 / -0
    Thanks everyone!

    I'm at 104,xxx miles. I did the battery check a couple days ago and it holds/charges fine. I will check the positive battery terminal in the front. It would be oh so sweet if it was as simple as a loose bolt! lol. I honestly had no idea there would be any effect from that guy.

    One thing that I did notice was a hashed wire/cable underneath the PS pump reservoir. It's under the positive terminal and hugging a aluminum cylindrical object. Does anyone know what that wire and that object is?
     
  8. Dave.0

    Dave.0 Helix & RMW Powered
    Lifetime Supporter

    May 4, 2009
    25,021
    13,497
    113
    Burbs of Philly, PA
    Ratings:
    +14,644 / 10 / -4
    Take a picture and post.....


    Holding a charge is one thing but a load test will really test the battery.
     
  9. MCS02

    MCS02 Moderator
    Staff Member Articles Moderator Supporting Member

    Jul 31, 2009
    11,188
    6,185
    113
    Male
    Ratings:
    +7,911 / 10 / -3
    Dave is correct a load test is the best way to check the battery
     
  10. BLKmini808

    BLKmini808 New Member

    Apr 22, 2015
    7
    0
    0
    Honolulu
    Ratings:
    +0 / 0 / -0
    Can anyone validate that a dead pump could trigger a battery light?
     
  11. Dave.0

    Dave.0 Helix & RMW Powered
    Lifetime Supporter

    May 4, 2009
    25,021
    13,497
    113
    Burbs of Philly, PA
    Ratings:
    +14,644 / 10 / -4
    Not that I am aware off but it could if you cant turn and hit a tree. (That's happened)
     
  12. Canusrufis

    Canusrufis RMW Powered R53
    Lifetime Supporter

    Nov 27, 2013
    208
    103
    43
    Male
    Winston Salem NC
    Ratings:
    +107 / 0 / -0
    yes it will. I've had the same issue as you when my PS pump went south. What happens is the battery is charged but quickly drains b/c the alternator charging the battery is "off" -- the system runs on the battery for a while until voltage drops. then the battery light. Theres a fuse under the dash - think its F34. If thats ok theres also a 100amp fuse under the bonnet for the ps pump. It the pump is gone it could burn this fuse (about $5-7 at local min shop). I'll try digging up my thread on this. I had to back probe the voltage from the pump to find the bad pump and the blown 100amp fuse. DON"T probe the red battery cable connected to the pump -- bad things will happen to the meter and probes.
     
  13. Canusrufis

    Canusrufis RMW Powered R53
    Lifetime Supporter

    Nov 27, 2013
    208
    103
    43
    Male
    Winston Salem NC
    Ratings:
    +107 / 0 / -0

    Heres the thread. Its F39 not F34. Happy to help... as is everyone else

    http://www.motoringalliance.com/forums/cooper-s/21151-battery-light-illuminated-alternator-battery-test-good.html
     
  14. Canusrufis

    Canusrufis RMW Powered R53
    Lifetime Supporter

    Nov 27, 2013
    208
    103
    43
    Male
    Winston Salem NC
    Ratings:
    +107 / 0 / -0
    btw, that 100amp fuse for the pump I had to completely remove to test it. It was open (failed) but when screwed in place was testing good (continuity). It was simply shorted across the terminals when screwed in place. With a replaced pump and new fuse -- everything worked as it should. :D
     

Share This Page