we have tried fuses soon as we plug for sat nav it blew same with every thing else

rubyred, July 2011

as it blowing the fuse WHAT EVER is plugged in to the lighter plug,the lighter plug socket is faulty, need to change it.
shine a torch down the middle see anything broke/loose
when you are inserting a plug the socket is going (S/C) short circuit which will blow the fuse

wirecutterman, July 2011

tempted to say you have a faulty satnav lead as it blows when you plug it in!

Steve, July 2011