Jim Streit. In answer to your question about testing clutch fan. My test is listening for the clutch fan to engage as I drive away for the first time every day. It should engage for approximately 1 min only when first moving the rig. If you hear it run briefly, then life is good! I do not know of any other test. I do not have the twin fan system so I have no idea how that system is supposed to work. I hope this helps.
2007 Itasca Sunrise 35A, W24 Chassis, Blue Ox, Toad-HHR. Retired