There are several things "wrong" with you block diagram. First, your cluster is an array of clusters, but you have turned off the indexing ability and you aren't displaying multiple elements in the array. It would appear that you just need a cluster input. If that's the case then you also don't need the for loop. This will clean your program up quite a bit.
Now with regard to your indicator light you could use a local variable as has already been suggested. However, it appears to me that the numeric elements in your cluster will always be used as controls and the boolean light will always be an indicator. I would suggest that you move the boolean light out of the cluster and make it a separate indicator. This will make the cluster such that you can convert to an array and use the summation rather than manually adding all of the elements. This makes your code become more versatile.
There are other things which could be done to make it more efficient also. I would suggest that you use an event structure to only run the code when the cluster value has changed.
I have implemented all of these changes to your vi in the attached vi.
You might also include code which only updates the "Error Light 9" indicator when its value has changed if your application required the highest efficiency.
