how to test tko speed sensor

[Denvervet]

I am having trouble figuring out why my new autometer speedometer won't calibrate. Been on the phone with them as well as tremec but still stuck. The issue is that the gauge works as far as the dial going thru all it's changes to begin to calibrate. Then when driving there is no reqistering of any signal at the gauge and thus no calibration. Checked wiring continuity from tko electronic speed sensor and it's ground. I checked for AC current being generated as per Autometer....nothing. Called tremec and they say that 2 wire sensor only creates a pulse and not current and just about never seen one of these be bad. That being said he did'nt really know how to "test" the sensor. Tremec also said it doesn't matter which of 2 wires is ground...and I already tried switching them around and got nothing. The last option I see is yanking the speedometer out and sending in..rather not lol....and Autometer said that it is almost unheard of for the gauge to all work correctly except recognize the proper signal.
Need some ideas

[vprace]

IIRC you can hook a volt meter up to it and pass a screwdiver back and forth across it to simulate the tooth wheel and it should generate voltage?

[Denvervet]

OK.........as is typical. Not a zebra but just a poor ground. Back to basics.