Now that's right....
Now back to the OP.
John,
did you get you non-working unit figured out?
Something ain't right,
there is a
HUGE difference between mode 1 and mode 3.
if you couldn't tell any difference, then your unit isn't working.
I'd prop the tank up and give her a good look,
if ya don't see something obvious,
I'd take the unit off and look at everything real good,
something ain't right.
pull the plugs apart, and hook the factory plugs back together,
if there's still no difference, your unit ain't working.
I'll bet if you do that, you'll see a bad wire somewhere, either that,
or your plugs aren't "snapped" together good, something.
JM2CW,
skip