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Correct jumpstarting?

Please describe the correct way to use cables to jumpstart my car. I’m afraid of installing the jumper cables backwards.

Wear some eye protection at the very least. Batteries don’t explode often, but when they do and you are looking at it, you usually go blind in at least one eye. Gat a AAA membership if you have enough money. If you drive old cars, you will be using jumper cables a lot more and will need instructions. Somebody is sure to volunteer the info soon.

You just need to make sure one wire is going to the terminal labeled (+) on both cars and the other one is going to the terminal labeled (-) or a piece of metal on the car’s body. Hook the (+) wire up first to avoid shorts.

I am also personally of the opinion that jump starting a car while the engine of the donor car is running is not good for the alternator, so I’ll leave the cables hooked up for a while to charge the battery before shutting off the engine on the donor car and trying to start the other car.

The most important thing is that you connect the positive (+, and usually red) terminal on one car to the positive terminal on the other car. Beyond that, there are other tips and techniques that people employ.

My favorite procedure is this:

*Park the cars near one another, but not so near that they might touch

*Turn off the engines, open the hoods, carefully identify the Positive terminal on each battery.

*Connect a jumper cable lead to one car’s positive battery terminal, and then the other car’s positive terminal. (Connect the positive cable first. This way, if you should accidentally touch the cable’s end to the car on the other side, you won’t generate sparks.)

*Connect a jumper cable lead to one car’s negative (ground) battery terminal, and then the other car’s negative terminal. (Some people recommend connecting the negative cable between two grounding points on the car, to avoid explosive sparks near the battery. If you can identify good grounding points, by all means use those, but if not, it is fine to connect directly to the batterys’ negative terminals.)

*If any of 4 battery terminals have corrosion, rock the jumper cable terminals back and forth to “cut” through the corrosion and make good contact with the car’s battery terminals.

*Start the car with the good battery. Have the owner turn off all electrical accessories (we do this for two reasons. First of all, we want no extra load on either car’s power system, second, if the dead car has an electrical system problem, the electronics in your car may be spared if they aren’t on).

*Let the good car idle for 1 minute with the engine revving at about 1000 RPM. This adds some charge to the dead car’s battery and makes for easier starting (idling the good car’s engine at 1000 RPM ensures that the car’s alternator is producing enough power to deliver charge to both batteries.)

*After one minute, have the owner of the dead car turn his or her ignition to On, then have them turn off all of the electronics in THEIR car. This serves the same purpose as above.

*Now it’s time to start the dead car. Have the owner start the car as they usually would. If it does not start, wait 2 minutes and try again.

*After the car is started, remove the jumper cable from the negative terminal of one car, and then the other. After the cable is removed, remove the jumper cable from the positive terminals.

*Close the hoods of both cars, allow them to idle, and you are set to go.

DO NOT CONNECT NEGATIVE BATTERY TERMINAL-TO-NEGATIVE BATTERY TERMINAL, as some just suggested. Use Click-and-Clack’s guide from the main Car Talk site, located here:

To clarify, connect the negative cables from one car BODY (or, Engine body) to the other car BODY (or, Engine body) . They are both grounds (negatives).
To help prevent possible damage to the cars’ electronics, from miss-connected jumper cables, make sure that BOTH cars’ ignitions are turned OFF while making the connections. Then, double check that POSITIVE terminal jumper (of one car) is connected to POSITIVE terminal (of the other car).

Every One Of My Cars Has The Correct Jump-Start Procedure In The [b] Owner’s Manual![/b]
I believe it’s a liability thing.

My car’s Ownner’s Manual takes six pages to cover Jump-starting. It includes everything you would possibly need to know, including all of the above advice. There are cautions for injury and damage, explanations, procedure steps 1-11, photographs, and illustrations, complete with arrows! One has only to familiarize themself with it. Should it be forgotten, there it is!

It’s always refreshing what one can learn from that little book.

True, but I think it’s not really fair to assume[b] that this person has their [/b]ownersmanual.

Mr. Josh, Sir …
It is possible that the owner has no manual. However, this illustrates the reason that replacement Owner’s Manuals are printed and available for most cars (they are for all of mine).

It’s a six P’s thing. Are you familiar with the six P’s?
Prior Planning Prevents P_ _ _ Poor Performance!

If you begin to connect the wrong cable, (the fourth clamp) to the engine/body, there will be SPARKS which will tell you, "DON’T touch me that way, you ______ ! ". This is your cue that your cables are intending to connect inappropriately. Reverse the intended connections and all will be serene.

I used to make my 4th cable connection to the negative battery terminal. I also used to follow the previous reply advice of:

If any of 4 battery terminals have corrosion, rock the jumper
cable terminals back and forth to “cut” through the corrosion
and make good contact with the car’s battery terminals.

Then I had a battery explode on me. It felt like a cherry bomb exploded in my ears and someone threw a bucket of acid in my face. I’m lucky I have my eyesight.

I now make sure my last connection is always to a location on the frame or body (away from the battery). And if I need to rock/giggle the clamps to get a better connection, I always disconnect the clamp on the frame first.

The goal is to never create a spark near a battery. The chances of it blowing up may be low, but if it does, you’re putting your eyesight at risk.

You should know something about the condition of the weak / bad battery before doing anything. Were the lights left on? Did the battery die over weeks of inactivity? If the battery is basically sound but weak and can at least power the instrument panel, it is pretty safe to jump start with the procedures discussed here and on the site – EXCEPT, the last connect to ground should be made away from the dead battery AT the HELPER car, in case the inrush current to the dead battery causes it to explode, boil, overheat, spark internally, etc. (Note: This is contrary to the owners’ manuals and the National Safety Council advice – but their collective advice makes no sense to me in today’s world of maintenance-free batteries that do do not emit much, if any, hydrogen gas in normal charging …)

Having driven the helper car to the disabled car, any high current flow OUT of the good battery is normal for a battery; but, batteries are designed to be charged slowly and incrementally so the lead sulfate and oxide is replated properly. Forcing a high reverse current on a battery that has little normal voltage in it, is just bad for the battery and may cause the plates to polarize, the acid to boil from resistance heating, or arcing across internal shorts from plate break-down debris at the bottom (the normal cause of battery failure).

Most of the time, when the weak battery still has the typical twelve volts, jumping batteries presents few hazards because the two volt difference between the batteries will limit any current surge. That is why we “get away” with it so often and consider it a motoring public obligation to help someone who is stranded, in the spirit of “what goes around comes around.”