Battery light issue

Reply

  #1  
Old 08-25-11, 02:00 PM
Gunguy45's Avatar
Super Moderator
Thread Starter
Join Date: Dec 2007
Location: USA
Posts: 20,860
Battery light issue

What could be the issue with my 2001 V6 Mazda Tribute? Battery light seems to come on randomly. Replaced the bat (5 yrs old, smaller than stock, and didn't pass a load test....was also run way low and charged back up every 2 weeks for a year when tranny was waiting for rebuild).

14.3V or so when engine is running (alt works).

Should I look at the ground wires...or maybe the belt for the alt?
 
Sponsored Links
  #2  
Old 08-25-11, 07:28 PM
Member
Join Date: Mar 2009
Location: Texas
Posts: 1,051
That is where I would start. Check and clean all cable connections, including grounds, and also any inside the fuse box under the hood, and consider replacing the serpentine belt, or v type belt if that is used for the alternator. I am thinking that under load the belt could be slipping, or the cable connections are poor both including those inside your fuse box.
 
  #3  
Old 09-02-11, 06:11 AM
Member
Join Date: Nov 2008
Location: Picardy, France
Posts: 14
Think about the regulator.
Its brushes are applied on copper rings revving twice as the engine.
Transistors are included in the regulator and are not eternal too.
On one of my cars, the red light used to light frequently although the tension was correct.
A change of the regulator has solved the issue.
 
  #4  
Old 09-02-11, 06:59 AM
Member
Join Date: Jan 2006
Location: Owen Sound Ontario Canada
Posts: 541
Alt lite should only come on when there is low voltage from the alt.
So. i would confirm a drop in voltage. I would wire up a gauge or tester in the car and see what voltage it is when the alt lite comes on. Just one of those cigarette lighter electrical plugins would do and measure with voltmeter from electrical leads.
When alt lite is on the voltmeter should drop to battery voltage (12-12.6 volts)
I would confirm that first then go looking. Post back with result of voltage please
 
  #5  
Old 09-09-11, 10:43 AM
Gunguy45's Avatar
Super Moderator
Thread Starter
Join Date: Dec 2007
Location: USA
Posts: 20,860
Just an update....

Wife went down to Tucson right after I originally posted...light still came on for her a couple of times. After she got back, removed the battery and tray and cleaned and checked all ground connections I could find underneath. No way I can get to them all. Checked with a meter between ground connection at battery to/between engine and body at several points...all about 1 ohm or less. Checked voltage and got between 14.4 and 13.7 or so depending on loads (engine fans, interior lights, A/C, etc). About 12.6 with engine off. Light was only on when all sorts of load was on and voltage was about 13.5 IIRC. I'm thinking the alternator is probably a little weak or worn, and with a load it's right at the threshold for the warning light...it does have about 140K on it.

She went to LA last weekend and still got a light occasionally...but she said it wasn't on for long any of those times and not at all on the freeway. Hasn't noticed it at all since her return home in short trips around town.

Planning to have the belts changed before going to anything else. After reading about it and looking at it...I just can't see myself doing it. First thing they say is "put it on a lift and remove splashguard"...there's just not a heck of a lot of room. I kinda doubt if my back and shoulders would be up to it laying in the driveway. Might find out about them checking or replacing the alternator....or at least checking and cleaning connections. An alt is about $200 and even if I order it from Rockauto or similar for less...you know how that works with shop labor. Just don't have an extra $300 or more right now. We'll see what they say about just the belt change.

We're not planning any long trips that we can't take the car for, at least not for a month...so if something happens here in town I can get it home.
 
  #6  
Old 09-09-11, 11:11 AM
Member
Join Date: Mar 2009
Location: Texas
Posts: 1,051
Back in time I once had an AMC Rebel with a flickering alternator light do to a weak alternator. I was still in school and didn't have the moola to replace it. I drove it that way for a year until reverse went out on the Borg Warner tranny it had. Drove it to the salvage yard with the light still flickering. Maybe that is why they call them idiot lights.
 
  #7  
Old 09-09-11, 01:00 PM
ukrbyk's Avatar
Member
Join Date: Mar 2010
Location: USA/ Pacific NW
Posts: 3,208
yeah, you keep checking voltage, but it's amperage that keeps your car going. if amperage is "just enough" it will trip extra draw from battery every time "it's not enough".

so you got one of them alternators sitting down at the very engine bottom, hah? just like 2 of our cars, Lexus and Eclipse. Actually, it's not that bad, once you get them up on a good jackstand. You can then remove wheel, splash guards simply pop out after few clips removed, and voila, there you are, all the pulleys and belts. of course, THAT BELT will be all the way behind the other belts, and you have to undo 3 of them, to get to the 4th one, he-he. I think on Lexus, I had to take main pulley off, to get to alternator belt. Nope, was on Eclipse.
But with a good jackstand, you can sit on the floor, legs underneath the car, and all this stuff will be about your mid belly level.
 
  #8  
Old 09-09-11, 01:15 PM
Gunguy45's Avatar
Super Moderator
Thread Starter
Join Date: Dec 2007
Location: USA
Posts: 20,860
Well...though it may cost a few dollars...I think I have more money than knee and shoulder joints that won't scream at me for 2 weeks if I try it. Or prevent me from walking more than 20 ft...lol. Now....if I had 4ft jackstands that might be different...I can stand up all day.

Yeah, sometimes ya gotta wonder what they were thinking. Older Honda Accord ('81?) I had required removal of a motor mount bolt and jacking the engine to change the stupid accessory V-belt.
 
  #9  
Old 09-09-11, 04:57 PM
ukrbyk's Avatar
Member
Join Date: Mar 2010
Location: USA/ Pacific NW
Posts: 3,208
and my so infamous 87 Taurus I could change alternator in roughly 15 seconds. mof, I got so good at doing it. and you can change VW Beetle old style engine in less than a minute. reckon, all that betterment we have now made it "easier" on us, tree shade mechs.

btw, reason I had to mess with Eclipse's alternator was because SHOP did chitty job replacing it. there's a bolt that is very long and hard, awkward to torque all the way back in. as a result, alternator was sitting crooked on that bolt, its pulley same way on the belt, and it killed alternator about 8 mths after job was done. alternator bracket chewed up half way through that bolt also, due to vibration and shear, and I had to become very creative to find a suitable bolt replacement.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'