Jump leads

[n brown]

jump leads are just like any other tool - if you need a set , get as good quality as you can ,then you get a tool for life that doesn't frustrate you every time you use it
i was lucky and found some excellent clamps at a boot sale, and got some long meter tails off a job. they do exactly what they should do

 

[Deleted member 65687]

I have always built one in by using a length of good thick (35mm2) cable with hella inline isolator switch between the hab and chassis battery pos. (earths are via chassis). Make sure ign is off operate isolator to connect then start as normal. Most American RVs have a relay switched version as standard equipment. Note only suitable with same voltage in both systems !

 

[trevskoda]

i think they reckon there will be a snatch/lurch when noddy in the drivers seat drops the clutch in.....anyway its designed to make you call the garage instead of sortin it yourself.

There is the same rotational snatch when you start the engine or change down gear,its folklore close your ears to it.

 

[Caz]

Are you talking about really modern vehicles Neil as my 08 Transit has dedicated terminals in the engine bay for jump leads?

My garage told me off years ago for jump starting my old Accord from my 04 reg Jazz, because it had an engine management system. They said it was OK once but never to do it again as it would cause problems with the EMS on the Jazz.

 

[Channa]

My garage told me off years ago for jump starting my old Accord from my 04 reg Jazz, because it had an engine management system. They said it was OK once but never to do it again as it would cause problems with the EMS on the Jazz.

Having worked for Honda the advise was correct, Rover 800 series the Jap engine ones suffered the same fate when jumped.

The Citroen XM was the earliest vehicle I remember with a distinct note in the handbook not to jump start. I am no electrician but my understanding in all cases is the sudden fluctuation in amps and volts confuse and can corrupt the ECUS with voltage spikes.

An alternative to jump leads is a booster pack which we used in the garages with built in surge wizardry, Over and above jump starting , don't take up much space decent set of leads, but have 12v sockets and usbs etc useful perhaps when camping to charge ,run other things built in lights etc

Channa

 

[harrow]

Connect one end of the red jump lead to the positive (+) terminal of the flat battery - do not let the other end of the red lead touch any vehicle metal - and connect the other end of the red lead to the positive (+) terminal of the boosting battery.

Connect one end of the black jump lead to the negative (-) terminal of the boosting battery and connect the other end of the black lead to a bolt or metal bracket, well away from the battery, on the engine block of the vehicle to be started. This is to avoid sparks right next to the battery.

The important part of using jump leads is the time of disconnection because of possible high voltage spikes.

After both engines are running,

stop the engine of the donor vehicle only.

Switch on the lights, the heated rear window and the heater blower motor, anything that requires a lot of power on the vehicle, this is to prevent any voltage surges or voltage spikes.

Disconnect the jump leads in the reverse order of connection, then switch off the lights etc.

There are no high voltage spikes when the jump leads a connected because one battery is flat reducing any voltage.

 

[davep10000]

The important part of using jump leads is the time of disconnection because of possible high voltage spikes.

.

Excellent advice, and totally agree with your sequence.
Having a heavy load on the battery 'smoothes out' any possible spikes.

Dave.

 

[reiverlad]

I always carry a mini jump starter pack with me & it lives under the drivers seat.
Very useful & have started a 2.8l diesel when someone had the misfortune to have a flat battery.

Started without a problem.

As has been said, the advice is to disconnect the starter pack within one minute.

Great piece of kit & would not be without one now