Easy way to test a trim gauge?

I bought a yamaha trim gauge off ebay...one of those new old stock deals...

I can get it to light up (with the black and blue wires)

but as far as making it actually do something..

For testing..I am plugging these wires into the actual motor:

Yellow, I plugged right into the battery

I grounded the black wire

There is a pink, orange, and black wire from the actual motor, looks like its going to the trim unit, that I connected to the gauge (pink to pink, orange to orange, etc)..

Should this thing not just power right up?

or is there a good way to test it by giving each the pink or orange terminal a voltage between 0 and 12 ?

thanks in advance!

Mike

[boats.net]

Yes it should as long as the gauge and trim sender are using same ground, can't have gauge connected to one battery and motor connected to another.

Weird.... I only have the one battery.....have you seen alot of these units as defective?

thanks
Mike