create new computer object in correct OUwith the name you want to use as the sql cluster name
disable the account
assign perms (I wound up giving the windows cluster, sql server service account user, and my domain admin account full perms to the new object — I also gave this object full perms to the windows cluster just to be sure it would work)
https://technet.microsoft.com/en-us/library/Ff367878(v=EXCHG.150).aspx