Testing a fuel level sending unit

Hey Guys and Girls

I'm testing a "new sending unit" with a meter (I'm in the ohm scale for now). It shows (in the car, on the dash gauge) thats its either on or off; full or empty.

I hooked the sending unit up to the wires and moved the arm and between 1/2 and 7/8 the needle on the guage moves from full to empty.

question one, can I test a sending unit with an ohm meter, should last least give me a basic idea whats what, I would think... Maybe you have to put juice to these for a real check?

You've been testing the empty light trigger... I think...

Last summer I was testing my fuel pump and without wiring diagram, I started checking the wires. If I remember well, there's a signal for the fuel level and one for the empty light.

Thanks Michiel, turns out this sending unit was out of an old Fiat I'm restoring and the ohm meter did work fine (once I switched to the right setting) and I had one wire, from the meter, on the base plate (ground) and the other on one of the terminals, the other terminal was the low fuel lite that worked as an off/on switch.

After I figured out the wiring I found a bad wire going forward; all fixed...YES

Oops, I was assuming you were testing an E30 unit. I was wondering about the arm, but then I remembered earlier models had different tanks, so maybe different fuel level meters....