Which battery cable, positive or negative, should I disconnect on my car to work on electrical?

Should I disconnect them both? Does it matter which order I disconnect them?

14 Answers

Relevance
  • Anonymous
    1 decade ago
    Best answer

    Disconnect the positive first. But should you be working on the electrical system on your car if you don't even know how to disengage the battery?

  • Anonymous
    1 decade ago

    In all reality, as long as you disconnect one of them, your OK, and No it doesnt matter if you do negative or positive first, just make sure the car is not running when you disconnect battery,

  • corron
    Lv 4
    3 years ago

    commencing the working vehicle is previous college & should not be performed on greater cutting-edge autos. don't have the main important grew to become on in any respect once you attempt to initiate the different vehicle. The electronics in greater cutting-edge autos are sensitve & if there's a difficulty in the vehicle that may no longer commencing you may injury the electronics of the single you're leaping it from. i comprehend a minimum of two people who broken the laptop boards in theirs jointly as attempting to bounce different autos. relies upon on what the vehicle is doing once you turn the main important to renowned no rely if it is probably a lifeless battery or some thing else. for sure if not one of the lighting fixtures come on the battery is possibly lifeless or if the top lighting fixtures come on yet seem to be dim the battery could be susceptible. If the motor particularly "turns over" yet won't "hearth" it may no longer be the battery. If it sounds like the motor is attempting to tutor over yet can not it may be the battery. in case you pay attention a clicking sound however the motor isn't attempting to initiate this is frequently an illustration of a bad starter solenoid & no longer the battery. do no longer stand close to the open hood of the two vehicle while somebody else tries to initiate the vehicle & ascertain you connect the two positves mutually (like others have suggested) & the negatives are linked wisely. i replaced into sitting at an intersection sometime while somebody in a carpark on the corner replaced into leaping a vehicle & between the batteries actually exploded & i've got faith it replaced into in view that they had the jumper cables crossed. many people say to no longer connect the black jumper cable to the two destructive posts on the batteries, yet I particularly have never had a difficulty in over 30 years of leaping autos this way

  • 1 decade ago

    always disconnect the negative cable , in newer cars where you have an ecu if you disconnect the positive cable only upon reconnection you might send a spike to the ecu which can lead to computer damage... i have seen it many times

  • What do you think of the answers? You can sign in to give your opinion on the answer.
  • Anonymous
    1 decade ago

    It depends on what you are working on, but to be safe , always disconnect both. Starting with the positive side first so that no arc is created that could pop anything computerized.

  • 1 decade ago

    It doesn't matter which order you disconnect the leads as long as one is.

  • 1 decade ago

    ALWAYS....I repeat....ALWAYS disconnect the negative first.....that's the ground wire. This way when you disconnect the positive, you eliminate the possiblitity of short circuit, if your wrench accidently touches frame or other metallic part of the car.

  • 1 decade ago

    Positive...although it would'nt hurt to disconnect both while you're at it.

  • Anonymous
    1 decade ago

    it does not matter. you mas as well disconnect them both, becaure you're going to lose all presets on your stereo and any electronic settings anyways.

  • R W
    Lv 6
    1 decade ago

    positive.

Still have questions? Get answers by asking now.