>Next day checked the fan operation (car cold, engine running, AC on) and only the passenger side fan came on.
Most common cause of this is failed low speed resistor.
There are 4 relays for the fans, a high speed relay and a low speed relay for each side. Your post doesn't say if you tried both relays on the failed side. If you jumped the high speed relay and got no fan, that sounds like the fan. But if you jumped only the low speed relay, then it could be a failed resistor which is very common and the way to test would be to jump the high speed relay.
I actually have a switch on my Boxster that grounds pin 85 on the two high speed relays so I can run the fans on high when I am on track.
Here are a couple of threads with more details:
https://986forum.com/forums/diy-project-guides/61513-diy-manual-radiator-fans-control.html
https://986forum.com/forums/diy-project-guides/76140-diy-manual-radiator-fan-switch-w-oem-switch.html
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