Why isn't it a good idea to use jumper leads on computerised vehicles nowadays?

Question

Why isn't it a good idea to use jumper leads on computerised vehicles nowadays?

Answer 1

Too much voltage for the design of the system.There are also "fusible link" wires that are designed to burn inside their coating when exposed to too much voltage. These can leave you stranded as they are very difficult to spot.It is best to remove and replace the battery.

Answer 2

The reason is that you could damage the cars computer which is it's brain leaving you stranded.  If you must give a boost connect only the hot cable (red) to the battery and the black cable you should connect to a metal part of the engine so that it is grounded.  As always make sure that your car is not running while you are conecting.

Answer 3

If you connect the cables correctly, there is no problem. If you hook them from battery to battery, positive to positive and negative to negative, there is no risk of damaging your computer.

All this gumph was put out by companies wanting to charge you three times as much for a set of jumper leads with a "spark arrestor" box built into them.

The maximum voltage available from the terminals of a car battery is somewhere near 13.2 volts. The alternator provides 14.4, so if excessive voltage was going to fry anything, wouldn't it be the alternator, and not a battery? Also, the E.C.U. takes it's current from a fused supply separate to the charging and starting circuit, so any erroneous voltage fluctuations would not affect the e.c.u. anyway.

Just connect the cables carefully, and leave the flat battery cars ignition switched off whilst you are conecting the leads from the jump car, and you will be fine. Also, do not use the engine as an earth, connect the battery terminals positive to positive, and negative to negative.

Read my source, I'm not lying.

Answer 4

get jumper leads with a serge protector and connect them with the positive to positive and negative to a good engine earth and turn the lights on on the flat battery car when disconnecting the leads and disconnect the flat battery car first than the other.

Answer 5

it isnt good at all to use  jumpers on the newer vehicles that are equiped that way because a total mess up could be very costly to have it repaired  

Answer 6

I have seen many vehicles still get damaged by doing this, either the alternator and or the (ECM) will get cooked.

Sometimes the voltage will pass through both the fuses as well as the fusible links so fast that they will not pop.

I also work with insurance companies that what me to determine what went wrong when a person is trying to make a claim and in these cases it was caused by using jumper cables.

Answer 7

reason being, as computers in the cars are sensitive to voltage spikes, and possibly someone hooking up the cables wrong.