[*Not sure where to post this, would a moderator mind putting it in the correct section?*]
Important: Old jumper cables could damage the electronics in newer cars. Old jumper cables without a surge protector can kill the electronics in newer cars! Before you jumpstart, check the jumper cables that they are of newer type and that they do have surge protection. The surge protector is easy to recognize because they are mounted in a small box on the jumper cable.
It is important to be focused and do the right things in the correct order when using jumper cables.
1. When connecting jumper cables, where a car has an empty battery will cause sparks when the last cable clamp No. 4 is put on (see the sketch drawing below). At this time surges up to 3000 volt (transients) may occur and which are a danger to the electronics in cars.
2. When connecting jumper cables make sure both the ignition keys to both cars removed from the ignition lock. This is to ensure that the keys are not in a position that allows the ignition system to be on.
3. The point of where connecting the last cable clamp No. 4 (See sketch drawing below) must be of good metal contact and as far away from the empty battery as possible. The reason for this is that when the battery goes flat it may form oxyhydrogen which can create an explosion if the cable clamp No. 4 is connected too close to the battery due to the sparks that will occur.
4. The car with full battery is the first one to start when jumper cables are connected on both cars and then start the car with the empty battery.
5. Important: The greatest danger of damaging the electronics in the cars when jump starting is when the cables are being disconnected!
When the car with the empty battery has started the jumper cables are to remain connected for a while in order to equalize the voltage difference between the empty battery and the full battery. This is not to cause sparks and power surges when disassembling the jumper cables when the electrical system on after the second car has started.
Point 1-4 is the order on connecting the jumper cables.
Point 5-8 is the order on disconnecting the jumper cables after the initial attempt has been made
(The jumper cables should be disconnected in the reverse order of connecting)