Battery Light flickers and yes I've read all about that problem here

[Jr's Sho]

My battery light comes on occasionly and goes off. It seems to be triggered under an electrical load like headlights on and turn signals at the same time. The light seems to glow and flicker at different times and even come on at night when i press the brake but it will then go out after releasing it.Two days ago I had my parking lights on, windshield wipers running, and then when I used my turn signal to change lanes, my ABS light came on and then went off. Well that seemed strange to me since it has nevered came on at a time like that. Well when I went to slow down and upon depressing the brake pedal, my abs light would come on and go off with the press of the brake pedal.And then my battery light was going on and off with the use of my turn signals.It lasted a few minutes and then my climate control resetted briefly and then came back on. And that seemed to reset when I used my turn signal with the radio,a/c on, and parking lights on. I checked my system with an alternator and battery tester at a GM dealership where I work , Imagine That wink and one tech said it was my battery and another said my alternator. I'm going to Autozone in a little while but I don't expect anything to show up considering my light goes out and isn't charging low at all times.I charged my battery up to 14.5 volts yesterday and it came on right away.I also cleaned every ground wire I could see under my hood to eliminate That problem.I refuse to replace parts when I'm not even sure what's at fault. Anyone had similar problems and any advice. After my trip to Autozone I'll post what they say.One more question, how do you check for a drain on your battery? Is it by taking your positive cable off and hooking a 12v test light to see if it comes on.Just wondering, but honestly I need some advice.

 

[SHOZ123]

My guess is the battery. What is the voltage at the battery when the car is running about 2k? Should be 13.5V or so. Then try it with all the electrical devices on at 2k. Should be 12.5V to 13.5V. Then with all the elctrical devices on and the engine NOT running check the voltage. It should not go below 11.5V for a minute ior two anyway.

<small>[ September 01, 2002, 03:35 PM: Message edited by: SHOZ123 ]</small>

 

[naval-avi8or]

The battery light comes on when the Alt./charging system is unabble to carry the load. If you don't get your Alt. voltage regulator replaced or get a new alt then your problems will only get worse.

 

[Jr's Sho]

Well one says the battery and the other says the alternator. Anyway I never got around To AuTozone yet, will do that tomorrow. Anyhow whenever I checked my battery volts after a few days of driving,it always reads between 12 and 12.2 with the engine off. Almost like the alternator can't pump any more juice into it. Maybe Autozone or Advance Auto can figure it out. On my way home this evening from working on my friends car, it came on, got brighter and then dimmer and then went out and came back on and repeated the cycle. A hand held battery tester at my work showed "12.2 volts-good-recharge ". A problem in the battery would have MOST likely shown up.Thanks for any input.

 

[SHOZ123]

You need to check the battery when the car is running.

Open Circuit voltage on a freshly charged battery should be ~2.1V per cell. On charge voltage on a fully charged battery should be ~2.3V per cell.

 

[SHOMA]

my thought would be an alternator... Why would the battery light flicker under load, if nothing is wrong? The battery will still be holding, but once that alternator finally craps out, you wont run long on the battery!
Kevin

 

[SHOZ123]

I too would suspect the alternator but if the battery is bad It may be outting too much load on the alternator.

If the elctrolyte level in the battery is or was too low, or if the battery has been discharged down to nothing a couple of times the plates will become sulfated and this severly reduces the useful capacity of the battery. Then if the alternator is a bit week it will cause the light to flicker.

You need to check the voltage at the battery under load.

BTW if the acid in the is too concentrated because the water has boiled off and the level is low you will get a higher voltage reading.

 

[naval-avi8or]

Your Voltage Reg is your problem. The Batt light is a shunt it only knows when the system voltage drops below 14 volts. A batt will always be below 14 volts. The light lets you know that your electrical system is be operated on the batt only. A flikering light indicated a weak voltage reg. However if you keep running on this you will destroy your batt as well, if you haven't already. If the alt can't supply the power to run the sytem it can't even get close to supplying enough power to recharge the batt after one/several starting events. If you test the system voltage with the engine operating and it is lower than 14.5 volts the alt needs replaced. You can het it rebuilt but my personal advice is to get one from NAPA or Autozone or any autoparts store that offers a lifetime warrenty. I had mine rebuilt twice in aprox 1 year intervals and I could have bought a lifetimer for less.

 

[Mishney]

I am saying alternator. I am on my third alternator now and each time it has done that same thing exactly. Time to replace the alternator.

 

[Jr's Sho]

I have an update. Advance Auto ran a test on my charging system and it said my alternator was putting out only 5 amps at about 2000 rpms. The guy who tested it said that was severely low and it would burn up my battery{he said it's supposed to put out 65 amps, is that right}? I'm not familiar with electrical systems so I didn't know. Well now I search for an alternator that won't cost me my lifesavings .Your friendly Autozone wants 180 bucks shoot Maybe NAPA will be cheaper with my dealership discount from GM . Either way I'll be spending some money I'll reply back if something else comes up. Posts are still welcome. wink

<small>[ September 02, 2002, 11:03 PM: Message edited by: Jr's Sho ]</small>

 

[LaTechSHO]

i think o'reilly's version is 130...

i'll check when i'm at work today... mtx/atx? year?

 

[Jr's Sho]

I ordered one today for two day air mail from NAPA, total price with shipping charges,185.00. And that's without tax. Hey if I own a SHO, I better get used to the expensive parts, right? Thanks for looking out for me though. Maybe I should have checked with O'Reilly's first. I guess I went for the store that offered the cheapest and quickest service considering my battery is now being drained due to insuffient amp output from the alternator. Hope it stays alive for the next two days though...

 

[91 Plus]

Hey man I had the same problem with my car..I changed battery and alternator which they told me to change..It ended up being the main cable leading to the alternator.It can me removed my 10mm wrench or something!!Anyways mine got all croded and rusty and wouldnt let the alternator charge the battery...Might want to look at that connection fast..Mine was covered by a little red boot!!

 

[LaTechSHO]

yeah..the mtx alternator is 135.99 at o'reilly... i think most of thier warehouses have them..i know the two in texas do... but i hope that solves your problem....

good luck

Louis

 

[Jr's Sho]

TodayI replaced my alternator with one from NAPA. Cost me about $200 total. No light has come on yet, that fixed the problem. Something that gave me trouble was the connection at the alternator from the main battery cable. It must have broke before because someone jammed it into the actual piece that bolts to the alternator and clamped it down. Well anyway when I took it off it fell into 2 pieces. But I just pushed the battery cable wire into the bigger piece, clamped it down, and bolted it to the alternator. Even if that was my problem{I doubt it was, my alternator was only putting out a few amps and slowly got worse over a months time}, the factory alternator was on there and it needed to be replaced anyways, unless someone replaced the previous one with one from Ford. Imagine that, 7 years and 106,000 miles later the alternator goes out. Thanks for all the input, the Shoforum really helps me out when dealing with my SHO.

 

[naval-avi8or]

I'm glad you got it fixed. One qiuck ?, when you got the new alt did they provide you with the warning note that would have been in the box. It states "WARNING battery must be fully charged (12.4 volts min) prior to installation". I never recieved it with the first alternator but when they rplaced the second one a day later they were vary adiment to supply me with the warning note.