Is there any material that can deflect or block magnetic attraction of magnets?
Yes, researchers in magnetism sometimes do experiments inside a room with mu-metal walls, so that the earth's magnetic field is almost undetectable inside. It would work just as well to shield the things inside the room from a permanent magnet outside.
if the truck sat for a while, the radio and computer are what drained the battery. they use power, at a very slow rate to keep the memory.
some of your problem sounds like what my son went through. Check wires and cables from battery to alternator for loose or corroded. loose ground. loose wires at starter. It sure sounds like bad ground. Can you wait til fails and have someone check for good continuity.good luck
For steady state fields, like that from a permanent magnet, the field can be shorted out by materials of very high permeability. The high permeability concentrates the magnetic field within the material so little can get through. There is a material called mu-metal which has a very high permeability and is used to shield magnetic components.
An iron box. The magnetic field lines are trapped in the iron and the inside is shielded of magnetism. Th
