trim gauge sending unit

[boston whaler]

I put in a trim gauge on my 15 whaler with 60 hp big foot, picked up wire marked trim gauges in harness under dash and it won't work. Can't seem to see any sign of a sending unit at the motor end to control the gauge. Does anyone know where it is. Ond guy told me it was part of trim pump but there are only two wires coming out of pump motor.
Thanks,

Boston Whaler