Front cooling fan runs too soon and too often

[maytag]

Hey y'all:
I'm not finding ANYTHING about this with a search. (LOTS of information in the threads about fans running after the engine is turned-off, which mine does NOT do).

My relatively-new-to-me '03 Boxster S (147k miles) has started to run the radiator fan VERY frequently. I noticed saturday that it would cycle a couple of times while sitting at a stop light. It wasn't more than 75d (f) here that day. The temp gauge shows just barely above 180d and holds, with very little fluctuation either direction.

This morning as I let the car warm-up before leaving the garage, the fan came on within about 2 minutes of starting the engine. Coolant temp wasn't even registering on the dash at the point. it only ran for about 30 seconds, then back off.

I've read about needing to clean debris from these radiators, so I'll get to that this weekend. I've also read about temp sensors that can go bad, but not clear on whether it's the same sensor feeding the dash / gauge?

Any help is appreciated.