Originally submitted by T:
==Jump Starting a Negative Earth Car:==
===Precautions:=== It's essential to keep any Disconnection or Connection Sparks that will occur away from both Batteries. Naturally, late Model Cars need a Spike Prevention Device fitted to the Jumper Leads otherwise the Connection and Disconnection Transients can blow any Electronics in both Cars.
===Jump Starting a Negative Earth Car Steps:===1. Make sure the two Cars are not touching.
2. Work one Jumper Lead at a time. Don't hold both Leads at once since the Ends may short together.
3. Keep the live Car's engine running the whole time, otherwise you will likely end up with 2 dead Cars.
4. Pick up the Positive Jumper Lead. Connect one end to the Battery Positive of the live Car. Connect the other end of the Positive Jumper Lead to the Battery Positive of the dead Car.
5. Pick up the Negative Jumper Lead. Connect one end of the Negative Jumper Lead to the Engine Block of the live Car.
6. Connect the other end of the Negative Jumper Lead to the Block of the dead Car.
7. Leave both the cars connected together with the live Car's Engine running for 10 minutes to let the running Alternator bring the dead Battery up. This minimises the Electrical load on the Cables, the Alternator in the live Car and will give you the Power of 2 Batteries and an Alternator when you crank the dead Car.
8. Crank the engine in the dead car. If it doesn't start easily, allow time for the dead car's battery to be recharged by waiting a minute or two between cranks. If the dead engine doesn't start, fix the dead car's problem before persisting. Remove the leads while you work on the car to void bumping leads together and causing damage and/or personal injury.
===After the Start is Complete:===9. Disconnect the recovered Car's Negative Jumper Lead from the Engine Block first.
10. Disconnect live Car's Negative Jumper Lead.
11. Put the Negative Jumper Lead on the Ground coiled up in a place where it cannot make contact.
12. Disconnect the live Car's end of the Positive Jumper Lead.
13. Disconnect the recovered Car's end of the Positive Jumper Lead.
14. Put the Positive Jumper Lead on the ground coiled up and away from any possible contact with both Vehicles' Electrics until you're ready to both Leads away. The idea is to keep the Connection and Disconnection Sparks away from both Batteries and any Hydrogen they will no doubt be producing under these circumstances. Batteries are known to explode during Jump Starts because these steps have not been observed so don't connect any Negative Jumper Leads directly to either Battery. If the leads are long enough to use the Starter Taps for the Positive Lead Connections, that can be an extra precaution. Starter Tap to Starter Tap connections for the Positive Leads is not always achievable.