[W126 Coupe] Broken Fuel Tank Sender Unit?

[Calvin Young]

My fuel gage went crazy, swinging wildly back and forth, low fuel light
coming on intermittently before it died altogether.  I suspect the fuel tank
sender unit.  

Can anyone tell me how to check this out (voltage meter on the wires?) or
could there be another cause.

I appreciate the response on the AC and plan to continue working that issue,
but I need to get this fixed first for obvious reasons.

Cal