@itsage, I know this is a little old.. trying to get this card working with a 2019 Mac Pro (long shot i know)
How can you tell which are pins 3-5 ? cannot see the connector well enough on the picture i cannot see the colors... bit high risk to guess 
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
.
@liam_hudson, It's been a while, but I would say to check the firmware version of the AIC first. The newer firmware may not work the same way. In terms of identifying the pin number, you can look at the photo below where I jumped pin 3 to pin 5 (short red wire).
LinkedIn | Youtube | Instagram
• external graphics card builds
• best laptops for external GPU
• eGPU enclosure buyer's guide
2021 Gigabyte Z590i Vision D [11th,6C] + RTX 3060 Ti @ 32Gbps-TB4 (Gigabyte Gaming Box) + Win11 [build link]
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
.