What should I test to determine why my cooling fan isn't coming on? My car started overheating in traffic and I pulled over, and neither radiator fans were on. It was fine as long as I was moving, and kept the heat on the rest of the way. Thanks!

Not sure what test but maybe a repair shop can test it... I do some minor work only on my cars and I would price a new radiator fan motor at a parts store... and consider installing a new one.