86 110, new singleviu gauges and fuel sending unit

86 110, V8

Replaced gauges with the RN kit speedo and +3
all but fuel work fine
fuel gauge doesn't register any level, but does display the red fuel low light (on the gauge itself) which is appropriate, since it thinks it is empty
replaced sending unit with https://www.roversnorth.com/parts/pl...w_fuel_warning

confirmed power and ground at sending unit
confirmed proper connection at gauge
confirmed there is fuel in the tank

still registers empty

Any guidance? wrong sender?

Thanks!
David Stephens