@hughesymendes great you got it working. Just to be clear you don't want to be drawing 2A at 5V from the Duet 2, I assume you mean that the relay is switching 2A max?

ah i thought about the fan ducts and not about the heat creap, yeah that could be not so nice....

@N131MG Thank you for your info on this. Its a great help 🙂
Love the test board by the way. Envious.

if its a relay module with a transistor to drive the coil, then maybe check the markings on the relay to see if its a 12v coil? it could get a bit toasty if fed 24v