ive been able to hear most of mine on previous vehicles.. 02 chev, 07 jeep srt8, 04 cummins. but I cant hear it on the new ram. must be in a different spot in the block thats harder to hear.
to check if its working, at night unplug it from the cord really quickly, you should see a blue spark as you unplug it.
if it arc's you know its working.