Uncle Ben's

Yeah last night I turned my Civic off for 5 minutes, but left the running lights and radio on, and came back out to my car and the battery was stone dead, I couldn't even popstart it with 3 people pushing it. So a friend throws a charger on it, and it starts and I drive right to Autozone which is where I bought the battery. They charged it and tested it, and said it was fine. The battery only put out 7.1 volts before I had it charged, so it was pretty much drained, also it's only 9 months old. How would I test to see if the alternator is bad, or if I have a bad ground or connection somewhere? I'm going to go out there in a bit to start it and test the running volts, amps, how many amps should it put out if the alternator is still good? I know it's supposed to put out 14.x volts when running, but that's all I know.

Uncle Ben's

Battery puts out 14.4 volts while running, so I'm assuming the alternator is fine.

gsrhatch2356

main thing that you should be looking at is if it can put out around 13.7v with everything on like radio, lights, wipers, rear defroster and whatever else you can turn on. I have seen alternators that were fine at idle with no loads but when you turned stuff on it dropped down to like 11v which was no good.

Uncle Ben's

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsrhatch2356 &raquo;</TD></TR><TR><TD CLASS="quote">main thing that you should be looking at is if it can put out around 13.7v with everything on like radio, lights, wipers, rear defroster and whatever else you can turn on. I have seen alternators that were fine at idle with no loads but when you turned stuff on it dropped down to like 11v which was no good.</TD></TR></TABLE>

Cool, I'll go back out and put all the accessories on and then if that doesn't result in a drop of voltage I'll take it to the other Autozone in town which has the charging system diagnostic tester. Thanks, I never thought to turn the radio etc. on and see how much it is putting out

Uncle Ben's

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Uncle Ben’s &raquo;</TD></TR><TR><TD CLASS="quote">Cool, I'll go back out and put all the accessories on and then if that doesn't result in a drop of voltage I'll take it to the other Autozone in town which has the charging system diagnostic tester. Thanks, I never thought to turn the radio etc. on and see how much it is putting out </TD></TR></TABLE>

Well it went down to 12.8 volts with the wipers, lights, radio, defroster and heat on full blast. Is that too low?

Uncle Ben's

Brought it to Autozone to get it tested, and it fell to 12.5 volts with everything running. The guy said the alternator is probably fine, and there is something drawing more voltage than it should somewhere, in his opinion. I got to looking around at all the main wires that go to and from the battery, and the alternator, and didn't find anything that needed attention, but I did find this hanging under my intake manifold, not connected to anything....




I've never heard of anything like this. My stab in the dark guess is that it's supposed to be hookep up to the battery terminals with the two C-connectors, with the white wire as a ground, and somehow it uses electricity to prevent corrosion from forming?

hgem1si

Wow that's wierd I've never seen that before.

I swear I seem to be having the same problem, I can't leave the radio on for 10 minutes while I clean out the inside of my car without the battery dieing.

What's really strange about it is it doesn't happen every time, sometimes it will last, and sometimes it wont.

Uncle Ben's

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hgem1si &raquo;</TD></TR><TR><TD CLASS="quote">Wow that's wierd I've never seen that before.

I swear I seem to be having the same problem, I can't leave the radio on for 10 minutes while I clean out the inside of my car without the battery dieing.

What's really strange about it is it doesn't happen every time, sometimes it will last, and sometimes it wont. </TD></TR></TABLE>

Yeah it happened at work last night, delivering pizza for my second/weekend job. I must have turned the car off a dozen times with the radio on for 5-10 minutes and it normally starts up perfectly fine, and I do this a few nights a week, but this time after five minutes everything was off when I went back in the car and it was so dead I couldn't even popstart it with a hell of a push from three guys. At this point I just wish the alternator was shot because I HATE with a passion electrical problems because I suck ***** at diagnosing them. I'd rather just change the damn alternator than have to go through this, or pay a shop 2x what the alternator costs to find and fix the problem.

Also another possibility. In the flooding earlier this summer, I ended up driving through at least two feet of water before realizing it, could this have pwnt a part of my charging system?

Uncle Ben's

Found this interesting bit of info reading through the archives of threads about voltage problems: "Sounds like a bad internal voltage regulator. New alt. There was a rash of these on 97-98 civics. there was a TSB on it." My car is a 98 Civic. Would a faulty regulator be respobsible for the low readings under load, and intermittent battery drain/failure to charge the battery?

gsrhatch2356

if the regulator was bad than more than likely you wouldnt see that 14.xx at idle, a alt with a bad regulator will either show battery voltage cause it is open or show like 16-17v when it is open field. the other thing I think you should check is when the car is running check voltage coming out of the alt vs. at the battery if there is anything more than .5v drop then there is excessive resistance in the charging wire. but due to the fact that it droped down to 12.8 I bet a alt will fix your problem, it just cant keep up with the loads on the vehicle.