Radiator Fan speed check?

[bowez]

Since the replacement fans only have 2 orange wires and Ground is there a good way to see which is the High and Low speed leads? Other than just hot wire it an see what happens. Basically I'm looking for a more definitive way to get it right (unless the replacements are aren't true 2 speed fans)

 

[Grog6]

On the 4.6 fans the middle tab is high, but you can try it on the bench with a battery; just put it in a vice to hold it. Watch your fingers! High is obvious, and will spark like crazy when you touch the batt terminal.