Volvo RWD Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 6/2025

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

voltage loss alt to battery

posted by  hardknocks! on  Sat May 24 03:54 CST 2008
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Sun Oct 12 06:42 CST 2014
[RELATED]

hello all
95 944T
this car has 13.8 volts at the alternator but it measures 12.8 volts at battery with accesories off.
(my 94 945T has 14.1 at alternator and 13.9 at battery.) why is the 94 dropping one volt from alt to battery?
i have cleaned engine block ground and other smaller blue ground, cleaned the battery terminals. cleaned every +12 wire at the battery.
also replaced a poor fusible link to the elect radiator fan that looked to be overheated and the insulation was falling off the wire. replaced the wire also.
i removed and cleaned the connections at the starter also.
i swapped in my good battery from my 94 a couple weeks ago, now its getting weak like the previous battery in the problem car.
how much voltage drop is acceptable?
the alt is old but putting out decent voltage, it has a brand new voltage regulator volvo brand.
i am stumped.
i guess its must be in the wiring but open to anyone with more experience on this subject.
thanks
mike







  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    voltage loss alt to battery

    uid 40935's pic
    posted by  Goatman on  Sat May 24 06:16 CST 2008
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Sat Jul 26 20:30 CST 2014
    [RELATED]

    Hi,


    That's too bad Mike! I'd run a new wire from the starter to the alternator. The old one might have rotted.

    Is the car dying?


    Goatman








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      voltage loss alt to battery

      posted by  hardknocks! on  Sat May 24 06:31 CST 2008
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Sun Oct 12 06:42 CST 2014
      [RELATED]

      hello
      i started to probe through the wire with the meter from the battery to the power source and within 6 inches of the battery the voltage went up .8 volts.
      i removed the + terminal and cut the sheath off to find a bulge in the big red wire. (defective)
      i cut it back where the wire looks good and am searching the garage to find
      a batterie terminal i know i have, but my garage is less than organized.
      probably just drive the 26 miles and get another one.
      thanks
      Mike








      •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

        voltage loss alt to battery

        posted by  walrus3 on  Sat May 24 07:07 CST 2008
        Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
        last visit: Mon Dec 2 14:20 CST 2013
        [RELATED]

        Hmmm... Is this the big battery cable or the smaller alternator wire?
        If it was the big battery cable I am surprised the starter would crank!
        --
        George Downs, Bartlesville, Heart of the USA!








        •   REPLY TO THIS MESSAGE    PRINT   SAVE 

          voltage loss alt to battery

          posted by  hardknocks! on  Sat May 24 08:22 CST 2008
          Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
          last visit: Sun Oct 12 06:42 CST 2014
          [RELATED]

          hello
          the big red wire was the culprit, the starter was cranking slow.
          about 5-6 inches from the positive terminal the big red wire was getting good voltage them when i probed closer to the battery terminal the voltage was much lower, i removed the black sheathing and seen a weak/bulging spot in big red wire.
          i cut back a few inches past the bad spot and put a new batt terminal on.
          now i get 13.50 at the battery and 13.9-14.0 volts at the alternator.
          this is much better but not as good as my 95 940.
          i may have to replace all the big red wires to the alt and starter.
          the repair brought the voltage at the battery up about .7 to.8 of a volt
          Art B gave me instructions to trace the problem by probing not just the connectors but the wire.
          thanks
          mike







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.