Ok. I just started up my car. everything was fine, but my battery light is on. No check engine light anymore. Earlier today I didnt have any lights but my srs light. Here is what happened.. my car has been sitting for over a year. The battery was bought about a year and a half ago, so it only has about 5-6 months of use on it. I have had to get it charged 3 times at autozone since I rebuilt my engine. Last night I had cel 41. The guy at autozone told me my battery took a long time to charge, but it finally did and it checked out good. However, since it took a long time to charge and it was a year just sitting inside my car. Could this be the problem of the cel 41 and my batt light coming on? I just need a new battery again? It makes sense to me in a way, but then again it isnt that old of a battery. Its a cheapo battery brand from autozone, so I'm sure since it sat so long and has had to be recharged 3 times, maybe it has just worn it out. My altenator is good, I had it bench tested. Just seeing if you all would agree. I dont want to waste the money for a new one, but if I need it I have to. Thanks in advance

Check the tension on your alternator belt first maybe. And then since it is a shitty battery, buy a good one this time, maybe an Optima.

P.S. And dont buy one from AutoZone, their quality in products is the cheapest and shittiest!

If the engine is running, and the batt light is on, that means your alternator is not charging properly. A simiple voltmeter/mulitmeter can test the alternator when the car is running. Just measure the voltage at the battery with the engine running, and it should not be below 13.4 volts. If it is, then your alternator is not charging the battery, which is why your battery keeps getting discharged. After you kill a car battery several times, it may not ever be able to keep a good full charge like it once did when it was new..

well I had my altenator bench tested at napa and it said it was good. However right now, if I go start it, no lights are on at all. It's weird. It's pissing me off b/c I cant figure it out, but I'll keep trying different things.. thanks

ok, just went outside to check it out. the belt seemed tight, so I started her up.. battery light comes on.... so I shut it off, tighten the belt, samething.. I take the neg terminal off while she's running and the engine dies... Now I know that is usually a good sign of altenator bad there.. but I just had the damn thing bench tested and it was good... I also replaced the 2 white cables that run from the fuse to terminal on the altenator w/ a nice battery cable. Is there any way to test the plug on the altenator and the plug that connects the alt,OPS,CPS,and Knock sensor harness to the rest of the harness? and if so what should I do and look for? thanks

Listen to the posts before. Check your voltage at the battery while the car is running. If it is below 13.5 volts then somewhere between your alternator and you battery is a problem. If you alternator passed a bench test then it is in the lines somewhere. a simple voltage tester used in the right way will lead you to the cause of this problem.

check your alternator fuse. if you have a good alternator, and its not charging.....you probably blew the fuse. trust me, i've gone through this before

ok I used this cheap voltometer that I have and it read 15v which I'm pretty sure is wrong and yes I was using it correctly. Anyways I kept it running and turned on my lights b/c its dark outside and it died. Now I dont know what to do. I guess I'll get a new altenator and new battery b/c if the altenator cant charge the shitty battery, then I need a new one and if the shitty battery takes so long to charge, I need a new one of them too. I'm just so scared that it's not gonna fix the problem. oh and the fuse is fine.

15volts is a good charge. I would try the battery. And check all of yout fuses under the hood. Even those big goofy looking ones.

all the fuses are fine... the black fuses in the box, how do you check those? also if it is just the battery, if the battery was weak would the light come on while the car is running and after I had my lights on and cd player the car died after about 10 minutes?

IF the battery is bad and the alternator is charging, liftign the negative terminal would yield a running car with no battery. The car shouldnt die. either the alt is bad or there is a wiring problem causing the alternator to not charge.

Terry

well damn. I'm stuck. The altenator passed a bench test, I replaced the positive wire that runs from the alt. to the fuse box and tested the wire for current, brand new belt and its tight, cleaned all connections. Is there anyway to test the actual harness plug that plugs into the alt.? maybe if I can test that and that would tell if the altenator is getting the connection. its just so weird, last night I had the same problem, earlier today I didnt have any problems, and this afternoon/tonight same problem. I'm stuck

ok being that the oil pressure switch is different on a 95-96 and 97-99, which would make the harness a bit different, does anyone know if the harness is adaptable for the two? like can I put a 97-99 harness on my 95? I'm not talking about the whole wiring harness, just the harness that plugs from the main wiring harness to the altenator, oil pressure switch, crank position switch and the knock sensor? thanks. If it does I'm going to replace all that to see if it helps my problem.

Do you have a good + connection to the battery? I had the same prob, and it turned out to be a bit of corrosion on the + side.

This was all after I bought a new alternator and replaced the battery.

yeah everything is clean

anyone know if the two harnesses are interchangeable other than the oil pressure switch? thanks

Did you ever figure out what your problem was? i've been having the same problem and have replaced the battery and alternator twice. also i've replaced the positive and negative terminals and wires and it still makes the battery light come on. not all the time though, just some of the time. if you figure it out let me know

Well, to update this, I had the same problem, after going through two alternators in a year the battery light was coming on. At RPMs above idle I was at about 11.9-12.4 volts. The problem then lies in the voltage regulator. In 2GNTs it is a part of the ECU and not serviceable by itself. Two options - replace the whole ECU, if you have the money to, or run a separte voltage regulator.

Do a search for 'voltage regulator' there is a write up on using an external volatge regulator for an 86 dodge omni. You splice into the wire at the ECU that controls the field coil output and run it to the module which you can mount anywhere (I have mine on the firewall). I hold a solid 14.4 volts even with most electrical accessories on. It is an easy and cheap fix. The part is 15 bucks and the pigtail another 10.

Here is the link:
http://www.electromotive-inc.com/pdf_files/neon99.pdf

It is for the neon, but works just as well for ours.
The battery light will always be on since the ECU no longer sees an alternator, but as long as you run a scan gauge or a volt meter gauge you can keep an eye on things.