Hi all. 83, 6cyl, gas,5 speed. I went to leave and my car would not start. I jumped it and it ran fine. I drove it for about 10 minutes and went home, shut it off and tried to start it and it was dead. I took it to Autozone to have it tested and while checking the alternator it died when it was put under a load, the tech said this usually means it is the battery.
The battery is 2 years old (Intersate I think) and it is a 4 or 5 year battery that is 400-450 CCA. The battery looks good with no corrosion and the fluids are good. This car came from central California and I am in Idaho, what are the chances it isn't strong enough for the colder weather? It is about 17-25 at night with the highs in the mid 30's.
When idling if you turn on the lights, radio or other device the battery gauge drops. When driving it also drops but only when you first turn the device on.
I think it is the alternator but wanted some opinions before I spend the money. One more thing. When I was looking at the alternator I noticed a connection (squared off male) on the alternator that wasn't connected to anything. I didn't see any disconnected females near it so I don't think this is the problem but do you have any thoughts?
How many times has the battery been discharged? After a few times the battery will loose it's ability to keep a charge no matter how old it is. As for the altenator...usually you can remove it and bring it in for testing....that would be the next culprit I'd look into.
that guy at auto zone doesn't know his a** from a hole in the ground. in order to test a charging system, your battery needs to be fully charged and in good condition. if not, you'll get false readings.
does the voltmeter seem to go up when you give it gas? I'd take the battery out and have it tested out of the car. sarin's right, after a few cycles of discharging, a battery will become damaged. I've heard that once a battery falls below 20% of its capacity, it's permanently lost its rated capacity. and to make matters worse, cold weather severely reduces the power you have left. if you need a battery that can handle that, an optima deep cycle or a deka intimidator is your best bet. they're constructed differently than standard wet acid batteries. it's also possible that you have a defect in the battery. every so often, a customer will purchase a battery and turn in their old one that's only a year or two old. and a load test reveals a bad cell. I've also had cases where batteries we sell are defective. we sold one a few months ago and it was returned defective last week, and we can't even get it to charge. I've tried and tried but as soon as we hit it with the load tester, it drops. I'd start with a battery. you don't need anything super powerful. I believe that year max calls for a group 35 battery. they're the most common in nissans. a group 35 should have between 550-600 CCAs if I'm not mistaken, and that'll start you in the coldest of days, with a reserve of 90 minutes if your alternator quits. you can't go wrong with a 35. a decent one from auto zone will run $55 and they're made by the same company that makes die hard, interstate, and most other common batteries. so don't be fooled by a name.
when the car runs, where does the voltmeter point? you could have an undercharging problem with the alternator too. undercharging won't leave you stranded, but full charge will never be reached. if you end up replacing the alternator, I recommend getting a battery anyway. a bad alternator can ruin a battery, and a bad battery can ruin an alternator. but it sounds like a battery issue.
about your alternator - you should have three connections. the thick lug at the back for the battery, the two-prong plug for the voltage regulator and charge indicator light, and a ground that connects to the alternator housing somewhere. maybe that's the ground? I didn't think the ground was important when I installed the alternator in the sentra cos it was bolted to the engine but was I wrong. it actually made all the difference.
at idle with nothing electrical on, you should see high 13s to low 14s on the voltmeter. if you turn on the lights or heater fan, it's not unusual to drop a little. even if you're driving, you'll see it fluctuate when you kick something on. but if it ever drops below 13, you have problems and should get somewhere quick cos you're discharging the battery.
if you feel really confident, you can check your battery for a bad cell with a hydrometer. the simple ones run like $2 and look like a big eye dropper with 4 balls in it. pop the caps off the battery and draw up the fluid from one cell at a time. on a fully charged battery, all 4 balls should float each time you test the cells. if all show dead (nothing floating), or if 5 show good and one shows dead, replace the battery. if it shows ok, I'd still have an auto pars store load test it to its rated CCAs.
my girl's car chills at right around 12-13 when idling, but when driving, it goes waaaaay up. also, the lights are a little dim when idling and with a little gas they brighten right up. car is perfectly reliable. when i replaced the battery a while back the guy at the parts store said it looked like the old battery had been fried from overcharging due to a bad voltage regulator. do you think he's right?
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-Josh - 94 accord ex coupe, 99 FZR 600, 88 Maxima (gf's)
How far up does it go? Anything over 14.5 is not good. Overcharging could be from a bad voltage regulator....or even from the altenator belt being way too tight.
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