Open the steering column. Check magnet and wires. If the magnets not centered, then center it and glue it into place. Make sure there's no glue on the outside of the magnet. Also, while you have it open put a small dab of superglue on the tip of the steering spring where it makes an "O". This will help keep it on better and help control a little.
If a wire is broke then get ready to do a pain in the butt soldering job.
take the chassis and put the 2 very short bottom prongs in the holes. then put on the piece with the magnet on the top rear shorter than the tall prongs. holt the magnet piece upright and then put on the clip and screw it back in place.