When jumping a dead battery, the general rule is to attach the jumper cables in this order: (+) on the dead battery, (+) on the live battery, (-) on the live battery, and then the engine block on the dead car.
What is the reason for attaching to the enging block on the dead car in stead of the negative battery terminal, and would it also be possible to attach the jumper cable to the engine block on the live car?
2007-01-04 07:35:20 · 6 answers · asked by OMGWTFBBQ!!1 3 in Cars & Transportation ➔ Maintenance & Repairs
You should attach them in this order + and - on running car + on dead battery - to the block or other good grounded area.
It has nothing to do with igniting fumes or any of that other non-sense such as heat. Heat is caused by using low quality cables. (ie. small gauge wire)
The real reason is that if you make the final connection to the dead battery neg. post they tend to spark and this can ruin the diodes in the alternator. Ruined diodes lower the alternators capacities for charging if not kill it altogether and can shorten it's life.
I do not believe that attaching the neg on the running cars block will change anything. This would work fine.
2007-01-04 08:45:47 · answer #1 · answered by Ta Dah! 6 · 1⤊ 0⤋
The reason for this connection sequence is that there may be corrosion between the battery cable and the battery posts on either the dead car or the 12 volt source car. Loss of voltage may never get the dead car started. Best to disconnect the dead car's battery and connect a known good, fully charged battery to the + side of the dead car with the negative side to the engine block. Another thought: you can buy an inexpensive battery post cleaner tool which will clean up both + an - posts on all your batteries. Remember that the battery cable has two ends, and either end can be corroded. A drop of oil at each connection may also help remove any existant corrosion.
2007-01-04 15:49:38 · answer #2 · answered by Phillip S 6 · 0⤊ 0⤋
The reason is if a spark was to happen at the last connection (to the dead battery)it could light any gases coming off the battery and it would explode.Hooking the neg cable to the live car block will give you some resistance and take away some of the jump starts effectiveness. Good luck hope I helped
2007-01-04 15:40:48 · answer #3 · answered by Rudedude 4 · 0⤊ 0⤋
The purpose for using the block is to reduce the chances of igniting any fumes that are produced from the heat of charging. It also charges the battery indirectly to reduce heat.
Yes you could use the block of the 'charger car' but expect it to take nearly 3 times as long to charge the dead battery, if it charges the battery at all.
2007-01-04 15:40:28 · answer #4 · answered by Lemar J 6 · 0⤊ 0⤋
I always have just gone POS to POS ; NEG to NEG.
Never used the frame or any other ground.
Actually, if you look the neg terminal just gets wired to the frame or chassis to make a ground, so i would say six of one, half dozen of the other.
2007-01-04 15:38:52 · answer #5 · answered by Anonymous · 0⤊ 0⤋
you should really use a jump box. its safer and won't fry an airbag system unlike car to car jumping would.
2007-01-04 18:59:14 · answer #6 · answered by MrCead 3 · 0⤊ 0⤋