Have a 2007 Saturn Ion.Owners manual says to pull a fuse before towing vehicle.The Roadmaster Inivisbrake system has a wire to trickle charge battery while towing.My question is if it is being 'charged' do I still need to pull fuse.I am the one who had the Saturn battery that died if not started in 3 days.Turns out that GM dealer found problem after 3 days.It was the radio 'module' not the fuse,which I had removed earlier but didn't solve problem .It is working fine now .Thanaks .