Thread: Jump Starting - negative terminal or body earth?

Originally Posted by kogvos

So what chassis point do you use in the Puma, considering the battery is under the seat and the jumper leads don't easily lend themselves to stretching too far?

Short of separating the jumper leads into two individual leads I haven't thought of a good solution yet.

My leads are entirely seperate. They don't need to be together except for neat ness. For your earth point, how about the door latch? The Air- Gas mixture should be rare enough at that point to be safe.

Originally Posted by kogvos

So what chassis point do you use in the Puma, considering the battery is under the seat and the jumper leads don't easily lend themselves to stretching too far?

Short of separating the jumper leads into two individual leads I haven't thought of a good solution yet.

Originally Posted by cuppabillytea

My leads are entirely seperate. They don't need to be together except for neat ness. For your earth point, how about the door latch? The Air- Gas mixture should be rare enough at that point to be safe.

Separate leads,
Jump donor nosed into side of the defender.
Positive through the window/ajar door and negative to engine block.
This minimizes losses on the earth circuit.


I've got my winch control box under the bonnet so I can use it if needed.
Last time I just pushed the button to connect the 2nd battery.

Originally Posted by cuppabillytea

My leads are entirely separate...

Originally Posted by alien

Separate leads...

Thanks both! Makes perfect sense. I'll split these up next time I'm crawling around in the cavernous back of the 90.

Originally Posted by alien

Separate leads,
Jump donor nosed into side of the defender.
Positive through the window/ajar door and negative to engine block.
This minimizes losses on the earth circuit.


I've got my winch control box under the bonnet so I can use it if needed.
Last time I just pushed the button to connect the 2nd battery.

My first thought was: How do you minimise losses when earthing to the frame? Then I completely forgot it when I suggested the door latch.
I must be getting old.

Originally Posted by cuppabillytea

I must be getting old.

Everyone was too polite to say.

As a matter of interest, jump started the tractor this morning from the 2a - positive lead battery to battery, negative lead from the tractor step to the galvanised bullbar on the 2a. Worked well, but the tractor battery was not flat, just a bit low - leave it parked for any time and it needs bleeding, and needs to be turned over a fair bit to get all the air out of the pump.

John

Originally Posted by alien

Not much I can add about why we don't put both leads on to the battery.


If your looking at jump start options with out pulling the seat etc.....
-The Anderson plug as you mentioned
-Fit power pins under the bonnet, I've noticed that Mack has these now.

The Scania I use has power pins fitted at the rear of the chassis. Seems strange, until you realise that that's where the batteries are mounted ( no, the pins are outside, the batteries are inside.... ).

Originally Posted by p38arover

The L322 has both + and - posts under the bonnet, away from the battery. One reason is that there is an explosive device on the +ve battery terminal which is intended to disconnect the battery in an accident.

The L322 had separate jump points because the pyrotechnic guillotine will ignite if you put power to it jumping off the battery itself. Pat