Anytime I need to jump a car, I always have to look up where to connect the jumper cables and in what order. I’ve only jumped a car a handful of times. It’s not really second nature to me, and I find myself second guessing myself each time, even though I’ve done it before. M biggest fear is shorting everything and causing damage.
Do you have any mental heuristic that help you remember how to jump a car properly? So we can prevent damage.
NEGATIVE is the one you have pay special attention to because negative energizes the body of the vehicle.
Anytime you want to do anything electrical related on a vehicle, always unplug the negative. Why? Because stray screwdriver or ratchet handles are always only millimetres away from exposed metal and could short out.
So just keep that in mind when boosting. connect negative last so that the body isn't energized while you're trying to plug in positive. Similarly, disconnect negative first, so the body isn't energized while you fumble with unplugging positive. Fairly straightforward. Even if you mess up the order it's not the end of the world you just might get some unwanted sparks.If everything is fused properly, you shouldn't cause any serious damage.
The thing you absolutely have to get right is matching pos-pos neg-neg, that's it. Or else that's when nasty things happen. But it's really hard to screw when things are color coded. Always use a flashlight or smartphone illumination.
and if you're an extra diligent boy scout, you don't connect negative directly to the battery so sparks don't ignite battery fumes. You should clip it onto a chunk of body or engine metal, even though some vehicles make it really difficult to find metal that is unpainted and will provide a low resistance path.
I just thought of an easy way to remember ...
the negative symbol is drawn with one line:
the positive symbol is draw with two lines:
There's your order. 1, 2
How come negative energizes the body of the vehicle? My understanding is that the negative terminal of a battery is like a ground. Without the second terminal attached, there is no directed flow of electrons (current). So, if your car is on the positive terminal, there is no current either. Given that the flow of electricity if very fast, it appears to me there is no difference in the order of connecting the terminals. Could somebody explain in simple or complex terms?
@MountainManJoe: Brilliant heuristic. Thank you!!!
hm now that I have a fresher mind, I realise the 1-2 thing only works for disconnection, not connection. Sorry, you'll just to reason it out yourself.
All good. At least I have the basic fir disconnection.
Simple it's like this.
Scenario 1: you're unfastening the cable from the positive terminal of you battery. Now lets say it's one of those nasty side post batteries where working space is very tight. You've got your wrench on the bolt, you turn it, and you strike the metal on the side of the engine bay ... bang! sparks. you pee yourself a little bit. Your date is disgusted and calls Mike to pick her up. The night is ruined.
Scenario 2: you unfasten the cable from the negative battery terminal. It doesn't matter if you hit anything because it's all negative. After you take it off, now the body of the car is floating. Neutral. No electrical path to anything. Now, smirking, you unfasten to positive cable, totally relaxed because nothing will happen. Even if you touch the body with your wrench, there's no circuit. You get the girl, ride off into the sunset and live happily every after.
Make sense?