Thanks for visiting us. As to your problem. It be one or more of a few things. First thing as you stated that this was intermittent, I would start looking for loose or damaged wires, damaged connectors too.
Check the wiring between the fan fuse (30A) and the fan relay 1.
Then check the wiring of between the fan relays and the ECM.
The next thing I would check is the Engine Coolant Temperature Sensor.
Here is a schematic of the system layout.
See picture attached.
Monday, November 19th, 2018 AT 1:44 PM