James - I think you have the sequence correct. I watched this video of an installation of a unit that appears to be the same as yours.

Easy to bench test if you replicate what the installer did in his video. Let us know the results please.

~ Dan
1951 Chevy 3 window 3100
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"My Grandpa Carl's Truck and How it Became Mine"
1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver)
US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)