Mike wrote:

Follow the positive battery cable away from the battery, it should go
directly to the main fuse which should be around 60 - 100 amps. It should be
blown, replace it. If it doesn't pull out you may have to unbolt it from
underneath. If you have no power at all you still have a blown fuse or fusible
link.

And follow the damn NEGATIVE connections all the way to the engine block too.

I know one lass whose negative connection to the block was relying on the
accelerator cable. Come deep winter and more cranking amps, the cable blew like a
fuse ! And I'd warned that as a recent secondhand purchase it needed a good look
over for any potential sillies but girls just can't think that way it seems, you
know the "but it was working" mentality.

Graham