we have a 2006 suburban at work 350, a/c, ps, 3/4 ton, 4 wd, 170k miles but many more idling hours. every so often it just stops, won't run, other times all locks (clicking), radio, etc. stops, new battery has lost charge, when something goes almost everything goes, then mysterously returns to normal.been in various shops and "fixed". Any suggestions? I'M wondering main fuse block or ignition switch or + or - cables have an almost break.the idea that everything is gone or close seems like a real hint,but I'm not sure. Comments? remember, high mileage and very high hours.