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Jump starting another car with a LeSabre
January 6, 2012 12:24 PM   Subscribe

Is there a relatively painless way to jump start another car using a 2000 Buick LeSabre?

The battery of a LeSabre is under the rear seat. There's a remote positive terminal under the hood that makes it easy to jump start the LeSabre, but I'm not sure how to jump start another car using the LeSabre without opening up the rear seat and using relatively long jumper cables, which is pretty tricky to pull off if even possible. A friend said that instead of connecting the negative terminal of the live battery to the engine block of the dead car I could just connect the negative terminal of the dead battery to the engine block of the live car, but I'm not sure how safe and/or effective that is. Anybody have any ideas?
posted by kmz to Travel & Transportation (14 answers total)
 
You're trying to create a circuit here. If you look at your car battery, you'll see that the negative battery cable will go to the car's body.

By attaching the negative cable to a clean, unpainted spot on the body or engine block you're closing the circuit to that battery, much like if you went to the negative terminal post itself.

The reason you avoid the terminal is the risk of sparking vapor that can be venting from the battery.

Does that help at all?
posted by Stagger Lee at 12:34 PM on January 6, 2012 [1 favorite]


OK, so in theory you could even just go engine block/chassis to engine block/chassis and not have either negative terminal directly connected then?
posted by kmz at 12:37 PM on January 6, 2012


Jump starting was somewhat addressed recently here which may help you understand the process better; one bit of advice to consider is checking the owner's manual; it should have instructions on jumping the car and using it to jump another car.
posted by TedW at 12:39 PM on January 6, 2012 [1 favorite]


OK, so in theory you could even just go engine block/chassis to engine block/chassis and not have either negative terminal directly connected then?

Yes, in most cars (and all modern cars since say 1960 or 1970) the negative post of the battery is connected directly to the chassis with a thick wire or strap.
posted by TedW at 12:40 PM on January 6, 2012


TedW covers the rest, that other thread is good, albeit a bit of an info dump.

If your owner's manual doesn't say anything specific, you can try going right to the block/chassis and you should be fine.
posted by Stagger Lee at 12:42 PM on January 6, 2012


Yeah, unfortunately the owner's manual of the LeSabre only covers jumping the LeSabre, not using it to jump another car.

Alright, I'm gonna try this in a little bit... will report on results! Thanks y'all.
posted by kmz at 12:46 PM on January 6, 2012


I'm pretty sure you have to have the cables actually connected to both terminals of the battery on the car doing the jumping. The negative-cable-to-chassis (or engine block) connection is only on the dead car.
posted by Thorzdad at 1:53 PM on January 6, 2012


"I'm pretty sure you have to have the cables actually connected to both terminals of the battery on the car doing the jumping. The negative-cable-to-chassis (or engine block) connection is only on the dead car."

Nope. Negative on the engine block is the same as the negative on the battery (give or take a slight bit of resistance).
posted by Pinback at 2:27 PM on January 6, 2012 [1 favorite]


You could always just park the cars perpendicular to each other. Cable length problem solved.
posted by matty at 4:03 PM on January 6, 2012


Thorzdad: "I'm pretty sure you have to have the cables actually connected to both terminals of the battery on the car doing the jumping. The negative-cable-to-chassis (or engine block) connection is only on the dead car."

nope, as long as it's wired in, the chassis is electrically equivalent to the negative terminal. There is the possibility of a voltage drop if the connection is dirty or loose; that's why it's recommended to connect straight to the 'donor' terminals.
posted by ArgentCorvid at 7:26 PM on January 6, 2012 [1 favorite]


Jump starting just needs solid connections between corresponding terminals of donor and dead car batteries, so jump starting another car from your LeSabre will need exactly the same wiring as you'd use to jump start your LeSabre from another car.

Just make sure that the last connection you make, and the first one you break, is nowhere near a possibly-gassing battery (the remote connection under the hood of the LeSabre sounds ideal); also make sure that you never accidentally let something connected to the red jump lead touch something connected to the black jump lead (this is easier if you fully connect the first lead before connecting either end of the second).

Minor voltage drops due to long wires or indirect connections are easily worked around by allowing the donor car to charge the dead one's battery for a couple of minutes before attempting a start. That way the "dead" battery will have accumulated enough charge to make a good contribution to the starting current, which means the jumper lead circuit has less to do. Turning on the dead car's ignition 15 seconds before attempting the actual start can help too, by giving the electric fuel pump time to do its thing.
posted by flabdablet at 6:30 AM on January 7, 2012 [1 favorite]


Agreeing with everyone here - the engine block and the chassis are both equivalent to the negative terminal on the battery being as they are connected right to it. The positive post in the engine bay is the same equivalent for the positive terminal. You can ignore the shape and just consider them connecting to the battery.

So how you'd transfer battery power TO your car is the same as how you'd transfer it FROM your car to perform a jump start.

I'd stick to the engine block earth, because finding an unpainted part of your chassis to connect to certainly should be very hard on a modern car. One of those nice sticky out aluminium/steel brackets that is bolted to the block is your best bet.
posted by Brockles at 7:11 AM on January 7, 2012 [1 favorite]


Just wanted to say that the jump worked perfectly this time, so thanks everybody!
posted by kmz at 10:51 AM on January 9, 2012 [1 favorite]


Glad to hear it.
posted by Stagger Lee at 11:45 AM on January 9, 2012


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