Edmunds Answers



  • zaken1 07/06/09 10:06 pm PST

    I'm guessing you determined the battery was good by testing it with a voltmeter when no power was being drained from it. That is not an appropriate way to test a battery. A battery on which the available power has diminished to the point where it cannot produce enough power to start the engine will still read full voltage when checked under a no load condition. A simple check you can make of your battery's power producing capabilities is to turn the headlights on, and then try to start the motor while someone watches the brightness of the lights. If the lights go out or get very dim when you turn the key to the start position; the battery does not have enough power to run the starter. This happens when batteries age. The only solution is to replace the battery.

  • zaken1 07/06/09 11:34 pm PST

    In case you're wondering how I can be so confident that it is only the battery; the car's electrical system cannot tell the difference between when the battery supplies starting power, or when it comes from a jump start. If a jump start will start the motor every time; a good battery will also.

    However, there is one condition where this does not hold true. And that is when the battery cable clamps are either not tightened, or are corroded on the inside surface. This corrosion is often not visible to the eye; but it will effectively insulate the cable clamps from the battery posts. When that happens, the battery is blocked from sending enough power through the cable clamps to run the starter; although it often will be able to supply smaller amounts of power, such as are needed to run lights. In a situation like that; connecting jumper cables to the battery bypasses the blockage from the corrosion, because the jumper cables connect directly to the battery cable clamps. So a jump start will supply enough power to run the starter, when the battery is either weak, or a good battery has bad cable connections.

    One of my friends has a car that becomes unable to start every few months. And I have shown him that all it takes to make the car start reliably at those times is to remove and thoroughly clean the cable clamps and battery posts with a battery cable service tool. So now his car no longer leaves him stranded when that happens.

  • sbrn362 07/07/09 5:50 pm PST

    Well I figured out last night what was causing car not to start!!! I know the symptoms were sounded like battery /alt . So I went out jumped it ,and i dont mean the normal jump were you wait a little rev the motor and so on! As soon as i touch the pos jump cable to the car in question car fully juiced just turn key its running!! So i got to thinking short of some sort computer s getting confused so on! Heres what it is. As long as i dont use the door locks or the key bobs what so ever car starts like a champ every time!!! Clock keeps time ! But if i push a door lock or use the key bob to lock or unlock It resets and nothing!! So i will simpley wont lock the damn car and throw away the key bobs lol!!!

  • zaken1 07/07/09 8:15 pm PST

    The last thing you wrote sounds like the alarm system is acting up. It would be helpful to know the year, make and model of your car; and whether it has a factory or an aftermarket security system. I would think that, sooner or later, you'll be in a situation where you want to lock the car. It should be possible to fix this problem without leaving you with a car that can never be locked again.


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