Charging System Problems

[somesailor697]

So starting about a month ago I have been having problems with starting my car I live in quebec canada and it has been getting fairly cold recently. First time I had a problem my car had sat un-started for a few days in freezing weather. Jumped it everything was fine. Now my red charging system warning light has come on. I assumed the alternator was bad so took it off and brought it in for a new one parts place bench tested it and said it was ok. So I put it back on car cleaned battery terminals and wire lugs and all connections on alternator. also cleaned the contact point at ground wire from battery to engine.-With the battery all charged from an external charger I read 12.3v at battery termianl's -With car running that drops to just over 11. -if I test at alternator +prong and on alternator housing I get 17v???(is that to high) -if I test from negative battery terminal to positive prong on alternator with car off I get 9v????(whatis going on there) I thought a wire ran directly from the alternator to positive termianl on battery. Does anyone have a wiring diagram of the charging system??? or is it possible I just need to replace battery??I am lost at this pointany help much appreciated

[ehoff121]

Welcome to GenVibe!More info would help here...What year/model Vibe?How old is the battery?

[somesailor697]

It is a 2005 FWD/Auto Base Model dont know if any options have impact regardless (ABS, Sunroof). I dont quite know how old the battery is I received the car from my mother as a gift last year. it has 145k km on it. I also neglected to include I checked all fuses and relays in the engine compartment and under dash.I have since cleaned all connections associated with alternator and battery and any grounding strap I could find with a wire brush, electrical contact cleaner and applied an electrical contact paste designed to improve electrical conductivity and prevent oxidation. Thanks

[ehoff121]

It is likely that this is the original battery, especially if it is ACDelco branded. The label would have wording to the effect of, "Made for NUMMI" if it is.Do you typically make a lot of short trips on local roads? This may not give the alternator enough time to recharge the battery, especially if you have the radio, A/C, lights, and rear window defroster all on at the same time.It may be that the battery is at the end of its useful life, especially if it has been run down in the past, e.g., headlights left on.I think a fully charged battery should read more than 12.3V...

[skimask]

Quote, originally posted by somesailor697 »Now my red charging system warning light has come on.That means something.Quote » I assumed the alternator was bad so took it off and brought it in for a new one parts place bench tested it and said it was ok.Ya, that really doesn't mean very much. That just says that the alternator is working properly under optimal conditions. And if it's a place like Autozone or something similar, I would put exactly ZERO faith in their testers and/or methods.Quote »-With the battery all charged from an external charger I read 12.3v at battery termianl's meh....should be a tad bit higher, but depends on how long it's been sitting after running and the state of the charge in the first place. If it hasn't been charged in awhile or it's been sitting for a few days, 12.3 is a tad low, but not terribly low.Quote »-With car running that drops to just over 11. That's because the car is running off the battery and NOT the alternator.Quote »-if I test at alternator +prong and on alternator housing I get 17v???(is that to high) Nope, not too high if you're bypassing the regulator. (just don't go doing that test very often! end up burning something else up!)Quote »-if I test from negative battery terminal to positive prong on alternator with car off I get 9v????(whatis going on there) That tells me you've got some rotten battery cables and/or connections between the positive of the battery and the positive on the alternator, which should be a straight shot, probably with a fusible link (or fuse) in the middle somewhere.Take that alternator back and get another one. And, as stated above, if your battery is over about 5 years old, probably time for a new one anyways. This one is probably on it's last legs in the first place. Or maybe not. I've had car batteries last for 10+ years without a problem...BUT...you know how that goes...first time you decide not to get a new battery is the last time it'll actually work and leave you stranded exactly halfway between where you were and where you were going, in the middle of the night, in a blizzard, and a dead cell phone.....