Do not use ohm scale with voltage applied..spell this fried meter
Using volt/ohm meter you can check for continunity between the input and base of the sending unit,(ground) and while in ohm mode (no power applied) there should be as he states 10 ohms at one end and about 90 ohms at the other with a smooth changing across the scale as you go from one end to the other...this checks out only the sending unit...to check your guage, you can do it two ways..ignition on disconnect your wire at the sender..guage will read zero..ground your wire and watch to see if the needle will start to rise..if it does, remove from ground at about 3/4 mark to allow it to cool off..this check both the wire and the guage.. the other method is to connect a 10 ohm resistor to ground and read scale with ignition on...connect 90 ohm resistor to ground and read scale..should be full deflection. If neither of the test shows anything you may have an open wire between the gauge and sender or bad ground at the tank..repeat test with a jumper wire to a good known ground..
report your findings...