This has nothing to do with the computers... Lower radiator hose cold after warm up is just what it seems. no water flow pull lower hose and see if you can find a blockage. Happened to mine once and I got partial flow by putting pressure at the top of radiator with a pressure tester. Blew some of the gunk out the lower opening...Later I had radiator cleaned and rerodded. now no problem.. hope this helps.. Later Mark.