and gain access to Reviews and Discussion of the 2016 and 2017 Ford Explorer Tech Tips, How to Articles, Off-Road Modifications and Events, Street Truck Mods and Events, and much more! Since 1996 our community has covered every aspect of the Ford Explorer, Ford Ranger and all vehicles based on this platform.

Register Today It's free! This box will disappear once registered!

Battery light constantly on (and low voltage on gauge)

Discussion in 'Stock 1995 - 2001 Explorers' started by Steeda90GT, October 5, 2008.

  • Searches ExplorerForum.com
    1. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      I was driving home from work and noticed my battery light flickering on and off. Once I got home I shut it off and started it again. Now the battery light on the cluster is constantly on and the volt gauge reads pretty low (Im pretty sure the stock volt gauge is an idiot light anyway, on and off...right???)

      The previous owner put the battery in, so I have no clue as to how old it is. I've owend the vehicle for over 2 yrs now. I cleaned the battery terminals REALLY well because there did appear to be some corrosion.

      So do I need a new battery/alternator, or both?
       
    2. Support EF


      Join the Elite Explorers for $20 a year

      Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose and fix problems yourself, and learn which modifications work without having to experiment on your own. Elite Explorer members see practically no ads, add your own profile photo, upload photo attachments directly to your posts and Media Gallery, create more private Conversations, and more. Join Today. Your support is greatly appreciated.



      to hide adverts.
    3. gavin

      gavin Elite Explorer

      Joined:
      September 27, 2002
      Messages:
      3,141
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      Anchorage, Alaska
      Year and Model:
      '97 Explorer XLT AWD 5.0L
      volt gauge?
      Explorer's have an ammeter. It displays the amperage
      When the gauge is in the middle, it means the battery is neither charging nor discharging.

      When the ammeter goes low, it means the battery is dischaging.

      If the ammeter stays low, it's possible the alternator is crapping out.

      as for the battery light... I dunno about that one.

      With the vehicle shut off, check the voltage on the battery with a multimeter. It should read over 12 volts.

      Then start the truck, with ALL accessories turned off, and read the voltage again. It should be at around 13v (sometimes I see as high as ~14 on mine).

      if voltage is low with truck running and accessories off, get the alternator tested.
       
    4. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      Pardon my lingo, I'm a Software Developer, not a mechanic so I just kind of make things up along the way.

      So what is the purpose of the battery light on the cluster? Does it come on when the volts are low and the alternator isn't charging properly?

      I also noticed the belt tensioner looked bad. The entire assembly appears to be loose..and when the truck is running, it wobbles.
       
    5. Blee1099

      Blee1099 Evil Asian Moderator Emeritus EF Vendor

      Joined:
      March 3, 2002
      Messages:
      14,050
      Likes Received:
      1
      Trophy Points:
      58
      City, State:
      Elkridge, MD
      Year and Model:
      91
      I would suspect the alternator? Does the tach bounce or any of the other gauges? I would take it to Advance auto or similar place and have the alternator tested. Grab a multimeter (digital one if you have one) and place it on the battery and start the engine and have someone keep the rpm's at about 1500-2000 constantly. See if the voltage drops below 13.8. Another thing you can do is start the truck and pull the negative terminal. If the truck dies, then your alternator is shot.
       
    6. gavin

      gavin Elite Explorer

      Joined:
      September 27, 2002
      Messages:
      3,141
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      Anchorage, Alaska
      Year and Model:
      '97 Explorer XLT AWD 5.0L
      maybe the battery light means voltage is low?
      and the ammeter would read low if the battery was discharging for whatever reason (ie, the alternator isn't providing enough juice to keep the battery charged and run the vehicle).


      I would still HIGHLY recommend, first thing you do, is check the voltage, as I mentioned in my first post.

      First check the voltage between the battery posts, with the engine NOT running. It should read around 12.5 or so.

      Now, start the truck, leaving ALL accessories turned off. At idle, the reading should be over 13... 13.5'ish is where it most likely goes.

      My guess, is that the battery light comes on, because the battery is below a set voltage threshold. It stays on, because the alternator isn't providing enough juice, or because the voltage regulator is toast and isn't providing the correct voltage.

      Either way, it would be the alternator.
       
    7. TheJackal

      TheJackal Well-Known Member

      Joined:
      August 11, 2007
      Messages:
      1,062
      Likes Received:
      1
      Trophy Points:
      0
      City, State:
      Mandeville, LA
      Year and Model:
      1999 Explorer XL 2WD
      The charging indicator ("battery" light) is controlled by the regulator. If the light is on, it means, as stated before, your battery isn't being charged.

      Take care of this ASAP, to avoid being stranded with a dead battery.
       
    8. fixxxer

      fixxxer Well-Known Member

      Joined:
      September 28, 2006
      Messages:
      1,457
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Aurora, Co.
      Year and Model:
      93 XLT 4X4
      The ALT light will come on if the alternator's output is too low. If your idler/tensioner is going bad, you could be merely dealing with belt slippage and that will cause your system to not charge the battery.
       
    9. corkey

      corkey Moderator Emeritus Moderator Emeritus

      Joined:
      January 3, 2008
      Messages:
      5,923
      Likes Received:
      4
      Trophy Points:
      58
      City, State:
      Elite Canuck,multiple ifs offender,, and musky maniac,, i wheel and i fish,,
      Year and Model:
      99 xls,96 xl,91,08 Ranger
      if the belt appears to be wobbling , and the whole thing is loose , i bet the belt is not turning the alternator enough to charge the battery properly cause the belt is slipping,,
      fix the loose parts first,
       
    10. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      Yes that's what I was thinking as well because the tensioner pulley does appear to be wobbly. I removed it and it looks like the whole unit is seperating.

      I'll try that first (only $40) and see if it works. If not, then new alternator. The idler pulley looks good and is spinning nicely (although the bearings are a little noisy)
       
    11. Cobraguy

      Cobraguy Elite Explorer

      Joined:
      February 22, 2008
      Messages:
      2,509
      Likes Received:
      0
      Trophy Points:
      36
      City, State:
      Phoenix...Greatest City on Earth
      Year and Model:
      1995 EB & 1999 EB 5.0
      Sorry Gavin, but that's not correct. Both my 95 and my 99 are VOLT meters. In fact, I can't remember Ford using an Ammeter in quite some time now.
       
    12. 4x4firefighter

      4x4firefighter Active Member

      Joined:
      May 17, 2008
      Messages:
      106
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Oneonta, NY
      Year and Model:
      99 Eddie Limited
      ok i got on to ask this very question. i just started having same issue. i replaced battery and instaled heavy duty altenator (all the dam lights). and it still does this! when it reads low volatage boys she is next to stalling out!!!:thumbdwn: if the vehicle is moving or u are above about 1200 RPM she is fine. its idling or stoping at a red light and everything dies down and almost stalls the car out, lights go real dim, etc......is the 1st guy have the exact same situation?
       
    13. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      OK, So I just came back from Vatozone and they tested my alternator. It failed.

      So I guess I'll pick one up. Where is everyone getting their alternators from? Vatozone has a new one for $189.99 that has a lifetime warranty. They also have a rebuilt one for $159.99 with a lifetime warranty as well.

      4x4firefighter - mine just had the battery light on cluster and very low reading on the "volt meter" lol

      The truck still ran fine.
       
    14. gavin

      gavin Elite Explorer

      Joined:
      September 27, 2002
      Messages:
      3,141
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      Anchorage, Alaska
      Year and Model:
      '97 Explorer XLT AWD 5.0L
      huh... I always assumed it was an ammeter.
      since it never moves, regardless if the voltage is at 12v or 14.5v.

      Only time it drops is when I have lights on, heater full blast, rear defrost on, and it's in drive with my foot on the brake. But even then, voltage is still at over 12.
       
    15. 99xlsdude

      99xlsdude Member

      Joined:
      January 14, 2008
      Messages:
      53
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Southern New Jersey
      Year and Model:
      1999 XLS 4.0 OHV 4X4
      About a year ago, I got a rebuilt one with a lifetime replacement warranty from Pep Boys for $120.
       
    16. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      Pep Boys quoted me $170 for the lifetime warranty one. I think the alternators are different between the SOHC and OHV, right?
       
    17. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      BTW - the $75 eBay ones are damn tempting..
       
    18. 98formulaLS1

      98formulaLS1 Active Member

      Joined:
      April 18, 2006
      Messages:
      159
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Virginia Beach, VA
      Year and Model:
      00 XLS
      this can happen when you purchase aftermarket alternators. There is a design flaw in the alternator. The problem is that when you truck is idling, and the serpentine belt is running much slower, it's not spinning fast enough to charge your battery during idle.
       
    19. gavin

      gavin Elite Explorer

      Joined:
      September 27, 2002
      Messages:
      3,141
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      Anchorage, Alaska
      Year and Model:
      '97 Explorer XLT AWD 5.0L
      yup.
      when buying a higher amperage alternator, you need to find out how many amps it puts out at idle.
      all alt's I've seen, are labeled with the maximum amperage output; which, of course, will not be seen at idle. Some of these put out the same amps as stock, at idle, some are even a bit lower.

      Basically what I'm saying... check the idle output when purchasing a high amp alt, do NOT buy it because it says "300 amp!"
       
    20. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      UPDATE:

      OK - I decided to buy a reman unit (lifetime replacement) for $129.99. I also installed a new belt and a tensioner (the original one was starting to split.

      Everything is great, no more battery light on cluster and my "volt gauge" isn't reading low anymore!
       
    21. kgbrgv

      kgbrgv New Member

      Joined:
      October 13, 2008
      Messages:
      3
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Los Fresnos, Texas
      Year and Model:
      1993 Ranger
      I have a similar problem. I have installed new battery and alternator. The volt meter is low and warning light is on. What next.
       
    22. gavin

      gavin Elite Explorer

      Joined:
      September 27, 2002
      Messages:
      3,141
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      Anchorage, Alaska
      Year and Model:
      '97 Explorer XLT AWD 5.0L
      wiring.

      it's possible a ground wire is either #1 not making good contact, or #2 is corroded.

      I would check the ground wire from the battery to the frame/engine block.

      also, try reading voltage at the battery. With and without the truck running.
       
    23. Steeda90GT

      Steeda90GT Active Member

      Joined:
      July 6, 2006
      Messages:
      448
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Central NJ
      Year and Model:
      99 Sport
      I agree. I cleaned up some of wiring just in case.
       
    24. kgbrgv

      kgbrgv New Member

      Joined:
      October 13, 2008
      Messages:
      3
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Los Fresnos, Texas
      Year and Model:
      1993 Ranger
      I will start checking on the ground cables and wires. Probably will replace terminal ends on both ground and positive cables. Both are factory ends. I did notice when I installed the new battery and connected the leads they were not making good contact. I removed and scraped inside of both terminals. The made enough contact to start and run but the charging light has been itermittently between starts coming on.
       
    25. gavin

      gavin Elite Explorer

      Joined:
      September 27, 2002
      Messages:
      3,141
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      Anchorage, Alaska
      Year and Model:
      '97 Explorer XLT AWD 5.0L

      my dad had a problem last summer with his Dodge not starting.
      It seemed after putting the battery charger on the battery, or jumping it, would work.

      turned out to be a bad positive cable to the battery. The cable looked perfect, but it was apparently corroded inside.
      Once the cable was replaced, he's had no issues getting the truck started anymore.

      It is possible that you are having a similar issue.
       
    26. kgbrgv

      kgbrgv New Member

      Joined:
      October 13, 2008
      Messages:
      3
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Los Fresnos, Texas
      Year and Model:
      1993 Ranger
      I installed new cable ends on post positive and negative.

      At first that seemed to solve the problem. About 2 hours later I checked again and had same issue again. Next I will try new cables!!!!!!!!!!!!! This is very frustrating. It has good enough connection to start with no problem. But there is not enough connection to send the correct amount of power to the alternator??? I will not give up. Cannot afford to have truck in shop. I have to same my dollars for Wall Street and Washington!!!!!!!!!!!!!!!!!!!!!!!
       

    Share This Page






    We Support Our Troops!