tachometer doesnt work on my '88 Pete 377?

The tachometer on my '88 Pete 377 doesnt work, so I first suspeted the sensor, as there was a broken wire on the end of the sensor. I replaced the sensor and it still does not work. Can I test the continuity of the wiring from the sensor end, with the other end attached to the gauge? Or, do I need to disconnect from the gauge itself, before I go testing the wiring? I want to eliminate the wiring before I go and purchase a new gauge.
thanks,
coadman

 

I checked the wiring for continutity, and had none, so I suspected a broken wire somewhere. Wiring looked good until I couldnt inspect it anymore, when it ran behind the ductwork behind the dash. I run another dual wire from the tach to the sensor, and that fixed my wiring problem, but tach still wouldnt work. I swapped a working tach from another Pete I have, and it worked in my '88. So, I guess the wiring was part of the problem, plus the tach gauge itself isnt working. I wiggled, tapped, ect, on the old gauge and nothing happend. So, guess I will go buy a new gauge. Someone told me they were about $200 new, but I have located some at a local truck salvage(which they guarantee to be good), for $100, so I will probably go the used route. Thanks for the tips!
coadman