Q: How can I set the node that should lose its vote for the Windows Server 2012 R2 50/50 vote split?
A: Windows Server 2012 R2 introduces functionality to enable a partition of a cluster to keep running even in the event of a 50/50 vote split.
In the event of an even number of nodes with no witness configured (which should never be the case in Windows Server 2012 R2--always configure a witness) then one node has its vote automatically removed to make the cluster have an odd number of votes again. This would allow one partition of the cluster to have a majority number of votes in the event of a split.
Instead of having this node randomly selected by the cluster, it's possible to specify the node that should have its vote removed in the event of an even number of node votes with no witness.
To do this set the LowerQuorumPriorityNodeId attribute of the cluster to the ID of the node that shouuld lose its vote. For example:
(Get-Cluster).LowerQuorumPriorityNodeId = (Get-ClusterNode savdalhv20).NodeInstanceID