 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Driving, Maintenance, Tuning / Maintenance and Repair / March 2008battery problem or alternator problem?
I have a 93 Nissan Sentra that will not start in the mornings as the battery will be totally discharged. The car starts easily when I jump the battery to another vehicle, and the battery charges reasonably well if I let the car run for a half hour or so. But if I leave the car off for more than a few hours (such as overnight) the battery is again discharged and I need another jump. This car is on its last legs and I do not want to spend the $300 it will take to install a new alternator, but a new battery might make sense if that is in fact the problem. Based on this information is it possible to determine whether the fault is in the battery or is it still possibly a faulty alternator? ps when I turn the car off there are no lights left on to drain the battery that I know of. > I have a 93 Nissan Sentra that will not start in the mornings as the > battery will be totally discharged. The car starts easily when I jump > the battery to another vehicle, and the battery charges reasonably > well if I let the car run for a half hour or so. But if I leave the > car off for more than a few hours (such as overnight) the battery is > again discharged and I need another jump. Sounds like the battery itself won't hold a charge, or the connections are not well made. > This car is on its last legs and I do not want to spend the $300 it > will take to install a new alternator, but a new battery might make > sense if that is in fact the problem. Any number of places will do a load test for free.  SignatureObama's childhood mentor, Frank Marshall Davis, was a communist. http://www.aim.org/aim-column/print/obamas-communist-mentor/ FO.newsgroup@gmail.com wrote in news:1342a8f9-16cd-43c4-8997- 10b25fae32bc@i29g2000prf.googlegroups.com: > I have a 93 Nissan Sentra that will not start in the mornings as the > battery will be totally discharged. The car starts easily when I jump [quoted text clipped - 9 lines] > Based on this information is it possible to determine whether the > fault is in the battery or is it still possibly a faulty alternator? You need a multimeter. If the alternator is charging the system's running voltage will be about 13.5-14.4V. If the alternator is not charging, the system's voltage (engine running) will be well below 13V. To check for a dying battery: Turn on your dome light. Try to start the car. If the dome light dims greatly or dims to nothing as the starter engages, the battery is likely pooched. > ps when I turn the car off there are no lights left on to drain the > battery that I know of. You could have some other key-off electrical draw. Any aftermarket components installed? Radio, speakers, fog lights, remote start, alarm, etc.? Use the same multimeter as above to check for amperage with the key off. It should be pretty much zero. Pull the negative battery cable and connect the multimeter in series between the cable and the battery's negative post. SignatureTegger >Based on this information is it possible to determine whether the >fault is in the battery or is it still possibly a faulty alternator? > >ps when I turn the car off there are no lights left on to drain the >battery that I know of. At this point I wouldn't think it was the alt regardless. A normal car battery can only be totally discharge a few times before it is totally ruined so at this point you probably need a new battery regardless but you need to figure out what the problem is before just replacing it and ruining another one. First thing I would do is unhook the battery when you get home. Hook it back up the next morning and see if the car starts. If it doesn't then you know the battery is bad. If it does start then you know something in the car is not turning off and running the battery down. Steve B. >I have a 93 Nissan Sentra that will not start in the mornings as the >battery will be totally discharged. The car starts easily when I jump >the battery to another vehicle, and the battery charges reasonably >well if I let the car run for a half hour or so. But if I leave the >car off for more than a few hours (such as overnight) the battery is >again discharged and I need another jump. The voltmeter is your friend. >This car is on its last legs and I do not want to spend the $300 it >will take to install a new alternator, but a new battery might make >sense if that is in fact the problem. The voltmeter is your friend. >Based on this information is it possible to determine whether the >fault is in the battery or is it still possibly a faulty alternator? No, you basically have no information right now. And it's also quite possible that some load is discharging the battery when the car is idle. You need to take voltage readings with the engine running and with the engine off, then disconnect a battery terminal and measure the current being discharged from the battery with everything turned off. If you have excessive load on the battery when the car is off, it's then time to start pulling fuses until you find what is causing the load. It COULD be the alternator pulling down the battery when it's idle... but you don't know without putting the meter on. >ps when I turn the car off there are no lights left on to drain the >battery that I know of. That you know of. That's the problem... there are lights like the trunk light and the glove compartment light that you may never see. Or maybe something else is drawing current. You have no idea until you measure it. Get out the meter and measure it. Almost certainly your battery is bad at this point, but you need to identify what is causing it or you will quickly ruin a new one. --scott Signature"C'est un Nagra. C'est suisse, et tres, tres precis." > <FO.newsgr...@gmail.com> wrote: > >I have a 93 Nissan Sentra that will not start in the mornings as the [quoted text clipped - 40 lines] > -- > "C'est un Nagra. C'est suisse, et tres, tres precis." Thank you for everyone's input. I have more information. I discovered that the battery is in fact draining when the car is off. I disconnected the ground terminal to the battery and connected an ammeter between the neg battery terminal and ground to measure the current drain, which is about 4 amperes. I went through the fusebox, fuse by fuse removing the fuses and looking for the faulty circuit (upon removing the fuse from the faulty circuit, the battery drain should drop to zero). The result, sadly, is that none of the fuses I removed affected the battery drain. So I am concluding that the short in the circuit must be occurring somewhere before the fusebox. Does this conclusion sound correct? Any advice? Thanks, -f the voltage across the battery should be about 13.2 volts with the engine shut off. The voltage across the battery should be about 15 volts (or at least something higher than 13.2) with the engine running. I am sure a place like Parts Source will test out your battery and your alternator for no charge. Call ahead to make sure. Ask if they can test it on the car or if you have to take it off. If the battery is 5 years old it is probably on its last legs. they don't last for ever. On Feb 22, 11:32 am, FO.newsgr...@gmail.com wrote: > I have a 93 Nissan Sentra that will not start in the mornings as the > battery will be totally discharged. The car starts easily when I jump [quoted text clipped - 12 lines] > ps when I turn the car off there are no lights left on to drain the > battery that I know of. Thank you for everyone's input. I have more information. I discovered that the battery is in fact draining when the car is off. I disconnected the ground terminal to the battery and connected an ammeter between the neg battery terminal and ground to measure the current drain, which is about 4 amperes. I went through the fusebox, fuse by fuse removing the fuses and looking for the faulty circuit (upon removing the fuse from the faulty circuit, the battery drain should drop to zero). The result, sadly, is that none of the fuses I removed affected the battery drain. So I am concluding that the short in the circuit must be occurring somewhere before the fusebox. Does this conclusion sound correct? Any advice? Thanks, -f > On Feb 22, 11:32 am, FO.newsgr...@gmail.com wrote: >> I have a 93 Nissan Sentra that will not start in the mornings as the [quoted text clipped - 27 lines] > Thanks, > -f I would maybe check/unplug the alternator. They can internally short and draw like that. I don't know where your fuse links are, but usually the next step would be to unhook those to ID which section of harness is the trouble one. They are usually located at the end of the positive battery cable, either on a power distribution box or starter. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos: http://mikeromainjeeptrips.shutterfly.com >Thank you for everyone's input. I have more information. I discovered >that the battery is in fact draining when the car is off. I [quoted text clipped - 7 lines] >in the circuit must be occurring somewhere before the fusebox. Does >this conclusion sound correct? Any advice? Sort of. The short in the circuit is occurring on something that is not powered by the fuse box. The number one offender in this case is usually the alternator. Disconnect the positive lead from the alternator and see if the drain stops. (Be sure to have the battery disconnected when you remove the positive lead on the alternator since it's always hot.) If that doesn't do it, your next step is to start looking for other things that are powered through fusible links and not from the fuse panel, and unfortunately this may require having a wiring diagram for the car to do easily. --scott Signature"C'est un Nagra. C'est suisse, et tres, tres precis." "Scott Dorsey" <kludge@panix.com> wrote in message > Sort of. The short in the circuit is occurring on something that is not > powered by the fuse box. [quoted text clipped - 10 lines] > easily. > --scott I have been chasing a problem like this one in a Reatta for a couple of years. Upon shutoff, you can measure about 4 amps for several seconds, then it usually shuts down to a milliamp load. Point is, some systems do not go dormant immediately, and you dont need to be chasing ghosts. Let it stabilize before rushing to conclusions. In my case, sometimes the Reatta would hold a charge, and in other cases it would not start. One night, my wife woke me up and said the taillights on the Reatta were burning. So this intermittent taillight problem was probably the real problem all along, and the initial 4 amp draw was just a decoy. I have had similar problems with an 89 Buick Regal, and traced it out for weeks until by luck I found the culprit. The seat belt retractor circuit was activating intermittently during the night and was draining the battery. Finally caught it in action, removed the retractor circuit relay, and solved the problem (this system was not necessary for safety. It was a convenience/comfort item)
|
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.