Jumpstarting a car

CrazyBones · Post by **CrazyBones** » Tue Sep 29, 2009 10:11 pm

Is it more efficient to connect to only the battery terminals or should one cable be connected to a metal part of the engine? I've seen it done both ways.

eGoCeNTRoNiX · Post by **eGoCeNTRoNiX** » Tue Sep 29, 2009 10:19 pm

The better the ground, the better the jump. I usually ground to one of the head bolts if I can reach them. Just me though.. Everybody is different

eGo

Executioner · Post by **Executioner** » Tue Sep 29, 2009 11:37 pm

Justlookin · Post by **Justlookin** » Wed Sep 30, 2009 3:53 am

Cars with top post batteries are easy to jump direct to the posts and works fine. Those with side posts are tough, mainly because you a lot of times can't get an easy access to the negative terminal and in some cases it's hard to get to the positive, but you gotta get that one for sure. If that's the case then it's OK to connect the negative to the engine block, but make sure it's a good clean connection. Always hook your negatives last between batteries when jumping and unhook them first when done jumping. A lot less chance off sparks and or potential fire that way.

normalicy · Post by **normalicy** » Wed Sep 30, 2009 10:47 am

Well, officially, the engine is a good grounding point, since the starter is actually grounded on the engine. Also, since battery fumes can build up, you want to connect the ground at the engine block last (further from the battery). I usually clamp onto my alternator if I can reach it, since it's a big hunk of aluminum with all kinds of holds for the clamps.

Err · Post by **Err** » Wed Sep 30, 2009 12:05 pm

I was always told that the reason for connecting the negative on the car to be jumped to the engine was to help prevent potential arcing that could occur when connecting the negative directly to the battery. Honestly, I've done it both ways and am not sure it matters. My Dodge is impossible to connect directly to the battery because it's underneath the car so Dodge provided "jump points" to connect to. I don't look forward to the day I have to pull the left front wheel and wheel well out just to replace the thing.

On a related note, if you have an aftermarket stereo that has external amps and such running directly from the battery, it's a good idea to pull your fuses when giving or receiving a jump. Otherwise, there's a chance that you can damage your amps.

normalicy · Post by **normalicy** » Wed Sep 30, 2009 1:57 pm

It's to prevent arcing because a spark will light any combustible gases in the engine compartment (the battery gives off hydrogen over time). That's the main reason you connect at a point away from the battery for the last connection.

And yes, you can mess your car's electronics up with a jump. Though, it'd have to be a pretty bad mismatch to do it.

renovation · Post by **renovation** » Sat Oct 03, 2009 3:01 pm

back in the day when cars had real bumpers (steel) i once jump a car just using a crow bar . I had both cars bumpers touching and used the crow bar as a link between both positive battery terminals. i know it was not greatest way or smartest. but it got the car started and off we drove.

d_b · Post by **d_b** » Sat Oct 03, 2009 4:54 pm

LOL, I did that too, reno except I used a piece of angle iron.

normalicy · Post by **normalicy** » Sat Oct 03, 2009 6:54 pm

Hey, if you're in a bind, it's completely allowable to pull a MacGyver! I've done similar.

Post by **FlyingPenguin** » Sat Oct 03, 2009 7:37 pm

Can't get away with that anymore. No more metal bumpers