Disconnecting battery to work on electrical system

[goku87]

Does it really matter which terminal you disconnect whenever you are installing stuff? I've always disconnected the + but only recently for some reason I keep noticing everywhere that you should disconnect the -? Does it really matter?

[IllusionX]

EDIT: either connection is fine.

What are you working on that you must disconnect the battery ? The dealer didn't even disconnect mine when they replaced the alternator.

[goku87]

Just a couple amps. I disconnect the battery because no matter how many systems I install, I have a bad habit of letting my live wires touch things they shouldnt. :)

[Tamago]

disconnect the + on the yaris. The + is constant everywhere in the car and the ground is switched. So disconnecting an unconnected ground do no justice. :wink:

What are you working on that you must disconnect the battery ? The dealer didn't even disconnect mine when they replaced the alternator.


lmfao disconnect whichever one is accessible, it does the same thing

don't listen to this guy :clap:

[IllusionX]

You are right one this one... i completely forgot about how the battery is connected to the car LOL.

edited my post...

[IllusionX]

Just a couple amps. I disconnect the battery because no matter how many systems I install, I have a bad habit of letting my live wires touch things they shouldnt. :)


I guess you shouldn't connect your live wire before you connect it to the amp.

[Uncle Yaris]

Does it really matter which terminal you disconnect whenever you are installing stuff? I've always disconnected the + but only recently for some reason I keep noticing everywhere that you should disconnect the -? Does it really matter?

Yes, it matters. If you disconnect the positive and accidentally short the wrench to ground, it can cause a fire or even an explosion (hydrogen gas in the battery - remember the Hindenburg?)

If you disconnect the negative, shorting to ground with the wrench won't do anything, since it's already connected to ground.

[AlexNet0]

Yes, it matters. If you disconnect the positive and accidentally short the wrench to ground, it can cause a fire or even an explosion (hydrogen gas in the battery - remember the Hindenburg?)

If you disconnect the negative, shorting to ground with the wrench won't do anything, since it's already connected to ground.


agreed, however this would only be if you touched the pos+ on the battery to a ground point on the car, regardless, good practice is to disconnect the neg-

[talnlnky]

all that matters is that you break the circuit.

If one wanted to argue semantics... you could probablly prove that the negative terminal is the one to disconnect since power flows from the negative to the positive (Its the negative terminal that sends out power), but really... who cares... the answer is...

either is fine.


I always just yanked fuses..... usually I didn't even do that.. haha. A good distroblock should be fused as well as your power cable (within 8inches of the battery).