Automotive Forums

I am having a problem with my 2000 Nissan Frontier.  Every now and then, and usually after I have just turned the car off after driving and try to turn it back on, the car completely dies.  When I try to start it, there isn't even a clicking or anything, the power locks don't even work. It's like there is no battery in there at all.  When I jump it off, it works for a few days to a week and completely dies again.  This problem started with my old battery.  I have a new battery now and the problem is still there.  Help!!!!  

We would begin with a physical examination of the battery.  If ok, proceed to the load test.  Load the fully charged battery (12.6V after a surface charge is removed) to 1/2 of its CCA rating for 15 seconds.  Voltage should be above 9.6 temperature compensating at the end of 15 seconds of load.  If good proceed to the current drain test.   Disconnect one battery cable and insert the ampmeter in series using the highest scale to begin with.  Once the 3 or 4 amp draw of the computers have been powered up, the current drain will reduce to support amperage only.  The normal current drain at this time is 70 milliamps + or - 25%.  If the current measured in amps is higher at this time, proceed to the dark/quiet test.  Make sure the vehicle is parked inside at night with no lights on.  This is so that you can see any light or indicator in any location including the glovebox, trunk, and engine compartment easily.  If a light is on somewhere when it is not supposed to be, correct that problem.  If there is no lights on, proceed to the sound test.  Disconnect the battery connection and repeat several times untill you can hear relays and other electronic devices going on and off.  Make sure the area you are working in is extremely quiet.  Investigate those devices that are making noise (due to them being energized from the power being switched on and off) and determine if they should be making noise or if they should not be at this time.  If you find a device that is making noise however it is switched off, and there should be no activity, that device becomes highly suspect.  Cycle that device and diagnose and troubleshoot its operation. One device that does not make noise and does not light up is the alternator when it has reverse leakage.  Simply disconnect the alternator and retest the current drain.  A clue to what electrical device is causing the current drain is the amount of current (measured in amps) it is drawing.  For example a sealed beam will draw approximatley 4 amps.  A smaller incandescant bulb can draw .333 amps (333 milliamps).  Check your lamp spec listing from your local auto parts store.  Using these methods, you can find any current drain in a few short minutes.   As a matter of good diagnosis and troubleshooting, finish with a performance test of the alternator, to make sure it is performing to its capacity.