This isn't an answer, but a continuation of the original Question:
I am still trying to solve this problem myself. I apologize for all of my "thinking out loud" posts above while I was trying to figure this all out myself. I should have read all the comments and links first before I began commenting! Forgive me, I'm a newb, lol!
I found and ordered an appropriate plug based on the answers above. Thank you all for providing the info to help find that! I was originally just going to cut and splice into the factory wire. I am waiting on the plug to arrive. But, I still need to know how to splice it onto my new BT module's cable. I don't how to match up the wires/pins from my new BT Module's cable to the port/socket/plug on the motherboard. Both have 4 wires. I'd assume they'd have the same function, but I am not sure if they are in the same order. Can anyone help me answer this so that I don't mess it up when splicing it? Does anyone know the pin line up of the socket this wire plugs into on the motherboard?
The Pins are labeled on the original Apple BT card, where the connection goes in (6-pin side), but not anywhere on the other end where the 4-pin connects to the motherboard. Also, I don't know what the labels stand for. Also worth noting, the pins in the plug, on the BT card's side, are in a different order than the pins in the plug on the motherboard side. Yes, the 4 wires are actually crossed b/w the two plugs. I really don't understand why they would have done this?!
Here the labels I've found, in case anyone can decipher them for me/us. Thank you in advance!
From top to bottom (only the middle 4 of the 6 pins are actually used) on MacPro original BT card:
Pin 2: D2 (1st wire on 6-pin side: corresponds to 3rd wire on the 4-pin plug)
Pin 3: D4 (2nd wire on 6-pin side: corresponds to 1st wire on the 4-pin plug)
Pin 4: D3 (3rd wire on 6-pin side: corresponds to 2nd wire on the 4-pin plug)
Pin 5: R15 (4th wire on 6-pin side: corresponds to 4th wire on the 4-pin plug)
(The 2 unused pins are also labeled: Top Pin 1: D5, Bottom Pin 6: D8)
Does D stand for Data and R for Radio?
This is BCM92046MD Card. I guess I could do a search for the pin layout of that part #. I will update if that yields valuable results.
Since I'm going to splice the 4-pin plug onto the 4 wires from my new BT card, I've got to get the wires matched up in the correct order, based on their function. But, I don't know their function to begin with, on either end!
The 4 wires from my new BT card are currently housed in a supposedly 'standard' 9-pin internal USB interface with 4 wires/pins being used. Although, I have seen some other versions only using 2 wires, and not all 4. I went with a PCI-e slot wifi bt card, rather than using the original stock location (which i think is a mini PCI-e bus?), for the sake of having external antennas & mistakenly thinking it would be an easier install. I did not realize the BT connection it came with would be incompatible. It is either Fenvi Model # FV-A436CD or Fenvi Model # FV-946CD. The model # listed on eBay and the #s/images on Fenvi website don't match up accordingly.
Link to the WiFi/BT card I bought: eBay Item # 392847805752
The seller told me the pinout for that cable is standard for USB 9 pin cables.
Top to Bottom:
GND Empty (Black/Green)
How do I match up this new BT card's 4 wires to the existing original BT plug/socket on the 2010 MacPro's motherboard?
Does anyone know how the new wires would coordinate with the existing socket?
Is it even possible to determine this from the pin labelings on the original BT card?
Thank you for any help/advice you all can provide me!
Andy will be eternally Grateful!