Engine Fan

[kozakvod]

Good morning all!

Yesterday, I'm humming down the highway back to Dallas from Amarillo and as I always do just scanned my gauges and I know my coolant temp was sitting at or just about 180. A couple minutes later my engine fan comes on (There are no hills there to climb that would cause a 20+ temp deg rise that would cause the fan to come on) and after I stopped chewing on the seat because it scared the hell out of me I'm looking around at everything and see no issues anywhere on the gauges except that the temp gauge is just about 180, not 200+ and that's not right.

I'm thinking the pneumatic switch on the firewall went out (for the record that switch did go out no more than 6 months ago and I replaced it) and kicked the fan on and not looking forward to hearing the fan running for the next 300 miles to the house. Then as the temp dropped, the fan cut off. Behaving just as it would if heating up pulling a hill. It remained off, never acted up again until just before Decatur, same thing, exact same temps, comes on, temp drops, fan cuts off.

I'm thinking it's a sensor or switch or something. Any ideas or directions to run in?

Engine: 2013 cm2350