I was emailing with Jim at source engineering about my overheating issue and mentioned I saw your issue posted today.
You should contact him today.
He commented that:
#1- the source fan should be direct drive not on an clutch or thermostatic fan.
#2 make sure when the fan was installed with the blades centered in the shroud edge- top to bottom and left to right
One more thing JIM mentioned to check is to
make sure the source fan is not installed backwards! it should be pushing air to the outside of the rear radiator
