JAL

My jump pack is fully charged and the connections I made were good. If I connect the jump pack directly to the battery I can get ignition lights. If I connect under bonnet I get nothing. As mentioned before the first time I connected under bonnet I had ignition lights until I turned the key to start then engine so it can only be a fuse between the under bonnet positive connector and the battery but which one is it? I cannot follow the wiring diagram to save my life sorry!

I own a Fiat Ducato 2008 Motorhome. I let the battery run down so got my jump pack, connected it under the bonnet, jumped in the cab, switched on the ignition, all lights came on properly so I turned the key to start it. There was a click and everything went dark. I can see that the jump pack is connected but the vehicle is not connecting to it any longer. There is no flow of electricity going from the jump pack. I’m guessing I must have blown a fuse but which one and where is it? your help will be greatly appreciated. Thank you. Jeff.