Dead tachometer

["cdrugly" <tgoodwin@xxxx>]

I did some work this weekend... changed the engine oil, tranny oil, 
oil cleaned pressure sender and replaced oil pressure sensor. When I 
got in the car after waiting 24 hours for the tranny oil to siphon in 
(next time I'll buy a pump), the tachometer is dead. Everything else 
is fine. Even my oil pressure reading is correct (as opposed to 80+). 
Could I have knocked something loose? I know there's an electrical or 
mechanical connection somewhere that sends RPMs to the tach, I just 
can't find it in my repair manual.

Can anyone point me in the right direction?