I'm almost sure it's a hardware issue.
I'd say the problem is the enclosure not being compatible with the console. the compatibility is based on the "USB to S/ATA" interface communicating with the drive and the console.
Try another hdd in the enclosure to confirm it's not the hdd, then/or try another enclosure.
or, if you just want a working setup instead of understanding what's happening with your current hardware, then go buy a new external USB HDD, not an internal+enclosure.
WD element, or another WD drives should work fine. it'll fix your issue and win time preventing you trying to find the problem.
if you want to know what the current problem is, then up to you, but I think it's the enclosure
Late last night I was able to get the hard drive initializing constantly through a hub where I plugged my hard drive in and it got power from a external power source. So I loaded up USB Loader GX and tried to play a wii iso. Loading the game however just blackscreened my wii so I turned it off and began to troubleshoot it more from other posts. I found a post where a guy said to put base 56 on slot 249, base 57 on slot 250, and base 58 on slot 251. However, this has now bugged out USB Loader GX by either not initializing the drive (Which I think I fixed my setting base 57 back on 249), having a blank UI when it loads up, or once I click to display Wii Games the whole application freezes, I can hear the clicking sound on icons but nothing loads. So as I have stated I tried to correct what I did by just setting base 57 back on 249 r52, but the problem still persists. I think it is probably the fact that I messed with the other slots (250, and 251). I will attach a system check as well to show you what I have done. I apologize for jumping the gun and trying to continue to work on this on my own as now I think I have put myself back on trying to get this working.
SysCheck HDE v2.4.0 HacksDen Edition by JoostinOnline, Double_A, R2-D2199, and Nano
...runs on vIOS58 (rev 6432).
Region: NTSC-U
System Menu 4.3U (v609)
Drive date: 07.12.2012
Homebrew Channel 1.1.2 running on IOS58
Hollywood v0x21
Console ID: 616505833
Console Type: vWii
Shop Channel Country: United States (49)
Boot2 v0
Found 45 titles.
Found 34 IOS on this console. 0 of them are stubs.
vIOS9 (rev 1290): No Patches
vIOS12 (rev 782): No Patches
vIOS13 (rev 1288): No Patches
vIOS14 (rev 1288): No Patches
vIOS15 (rev 1288): No Patches
vIOS17 (rev 1288): No Patches
vIOS21 (rev 1295): No Patches
vIOS22 (rev 1550): No Patches
vIOS28 (rev 2063): No Patches
vIOS31 (rev 3864): No Patches
vIOS33 (rev 3864): No Patches
vIOS34 (rev 3864): No Patches
vIOS35 (rev 3864): No Patches
vIOS36 (rev 3864): No Patches
vIOS37 (rev 5919): No Patches
vIOS38 (rev 4380): No Patches
vIOS41 (rev 3863): No Patches
vIOS43 (rev 3863): No Patches
vIOS45 (rev 3863): No Patches
vIOS46 (rev 3863): No Patches
vIOS48 (rev 4380): No Patches
vIOS53 (rev 5919): No Patches
vIOS55 (rev 5919): No Patches
vIOS56 (rev 5918): No Patches
vIOS57 (rev 6175): No Patches
vIOS58 (rev 6432): USB 2.0
vIOS59 (rev 9249): No Patches
vIOS62 (rev 6942): No Patches
vIOS80 (rev 7200): No Patches
vIOS249[57] (rev 21010, Info: d2x-v10beta52-vWii): NAND Access, USB 2.0
vIOS250[57] (rev 21010, Info: d2x-v10beta52-vWii): NAND Access, USB 2.0
vIOS251[56] (rev 21010, Info: d2x-v10beta52-vWii): NAND Access, USB 2.0
vIOS512 (rev 7): No Patches
vIOS513 (rev 1): No Patches
Report generated on 11/09/2018.