I agree with Term, you have a short most likely connected the work you just did.

Disconnect all power to the CD changer.
Put all else back the way it was, include removing molex plug and splicing wires to original
Replace fuses one at a time.
See if the problem goes away.
If not, check again that all of your work has been reversed to the way it was, if show it is something else
If all is OK, plug in the CD player to see if fuse blows.
If fuse blows disconnect CD player and connect molex plug to see if fuse(s) blows
If all is OK, wire in the molex plug to see if fuse(s) blows.
If fuse blows, the molex plug is bad or is wired wrong or the power wires are touching.
When you are 'done' the problem is gone, or, it is something else--just a coincidence, or, your work has caused a problem elsewhere.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas