How do you jump start a 24 volt lorry with 12volt car?

Answer 1

As far as I know you can only do it if your lorry has two 12volt batteries connected in series, ie with the positive of one battery connected to the negative of the other. If so, then you connect the car jump leads to ONE of the lorry batteries in the normal way (car positive to lorry battery positive, car negative to lorry battery negative). Try to start the lorry like this, with the car engine running at a fast idle, with all electrics on the car turned off. If this doesnt work, try again with the jump leads connected to the other lorry battery ONLY. If this doesnt work, then both lorry batteries are too flat and you'll have to jump off a 24volt lorry / charge or replace the batteries. Jumping off a 12volt car usually only works if you have one lorry battery which is ok-ish, and you use the jump leads to "help" the weak one with the car. Good luck from Norn Irn!