A broken cooling fan can cause your engine to overheat and even cause damage to the water pump. Learn how to troubleshoot an electric fan that refuses to work. If you have a basic knowledge of electricity and electrical circuits, this will be an easy task.nstructions. Check for broken wires or loose connectors around the fan circuit. Inspect connectors at the fan motor, relay, sensor or heat sensitive switch, and the Electronic Control Module (ECM)--your carâs computer control system. Also, make sure to check for a possible blown fan fuse.