Jump starting a vehicle

[Gary_in_Indiana]

I had occasion to use jumper cables to try to jump start a dead battery today and it brought a question to my mind. If the running vehicle has a battery strong enough to have started that vehicle and the alternator is functioning properly why wouldn't the dead vehicle start 100% of the time?

I'm sure I'm missing something obvious here, but if I took the good battery and put it in the dead vehicle it would then start so why won't that same vehicle start when using the cables?

Goodness knows I've used jumper cables probably as much as anyone and more than most, but this question never hit me until today.

 

[Thomas]

Today's vehicles w/computer boards etc..I get a little nervous jump starting a dead battery..mostly someone I don't know,for I heard of others giving a helping hand than ending up paying a repair bill.

 

[RoyJackson]

Today's vehicles w/computer boards etc..I get a little nervous jump starting a dead battery..mostly someone I don't know,for I heard of others giving a helping hand than ending up paying a repair bill.

Jump starting shouldn't be any problem...just make sure you've got the cables connected right.

 

[Thomas]

A service tech said once..when one jump starting another try and have both vehicle the same.

Example..don't try and jump start Ford 250 w/Chevy S10,for it drains the Chevy S10 system also heats up wires relays etc..and always unplug the computer board w/the vehicle your jumping with..would this be true?

 

[jimmoore]

You always loose a lot of power through the jumper cables, they ARE much longer than the regular battery cales. Hook up the cables and let the running vehicle charge into the other vehicle battery for about 15 minutes and then try to start, much better!

 

[Egon]

First is a proper set of jumper cables. Like Franz metioned in another site welder cable works wonders when used as jumper cable to transfer electricity.
Then follow proper proceedures when hooking up the cables.
As Jinman said let the dead battery build up a little.
When doing the actual starting it doesn't hurt to have the headlights and heater on on the the vehicle doing the jumping. This may prevent a surge when the other vehicle starts. It also doesn't hurt to rev up the jumper vehicle a little when trying to start other vehicle.

Egon

 

[Gary_in_Indiana]

<font color=blue>"You always loose a lot of power through the jumper cables."</font color=blue>

OK, that answers my question and makes sense. Thanks! /w3tcompact/icons/smile.gif

 

[I_am_the_Walrus]

A friend of mine recently jump started his Jeep Grand Cherokee,newer model /Mopar battery less than 2 years old,he noticed the post was a little loose inside the battery and when he attempted to jump start the Jeep....Boom...the battery exploded in his face,He had a pair of glasses on and I am sure that is the only thing that kept his eyes from getting acid in them.

 

[Jeff396]

I think the correct way to jump a vehicle is to make the final connection to the car giving the jump and then not to the negative side of the battery. You would rather want to make your final connection to a good ground somewhere else under the hood. That way if there is a slight spark combined with the battery leaking fumes the spark shouldn't ignite it. My LHS has a remote battery like lug to make the ground connection to for jumping on the inner fender well away from the battery.

Jeff

 

[chim]

Gary, here's an excerpt from a reply of mine on another recent thread:

"Just be sure to get "manly" clamps. The last set of jumpers I bought were real heavy duty, but often would not start a "dead" vehicle without first connecting and giving it some time to charge up. I couldn't locate better clamp ends, so I replaced them with 4 Visegrips. Absolutely amazing difference."

There are a few things that work against you when needing large amounts of current. Cable that is too small. cable that is too long and a lack of a good solid connection. With the right jumpers, the dead vehicle will turn over just like it had a new battery under its hood. When I jump a vehicle, I want it to start NOW. If time is not important, you could use one of those "charge through the cigarette lighter" gadgets, take Wifey out for the evening, and try it when you get home.......................chim