Doing a cummins conversion , motors a 1996 cummins , just trying to figure out the whole tach pulse thing . I know the 2nd gen dodges use the alt and ECU to control the tach signal .
I have a full harness and gauge cluster , was consider using the whole setup but my alternator is a custom one from Pa Performance ... 200 amp single wire , so that was not a option for either the stock or a adapter from Dakota Digital .
I know autometer makes a take that will work off a 4 pulse indicator . Cummins has a 2 pulse harmonic balancer , I was considering cutting 2 more notches but don't want the balancer out of wack .
I do see autometer makes a 2 pulse for motorcycles ...
I am doing a custom gauge pack in a cheby so I need to find a 5" tach to fit next to to the speedo .

Any thoughts on this would be great .

 

you are installing the cummins into what? year? if your using just an aftermarket tach you can use the dakota digital and tap into your alternator rectifier , or read of the flexplate tone ring , iirc you can use a low voltage tach and run it from the balancer pulley but you have to machine 2 more grooves on it.

marco.

 

Wanted to stay with the same style autometer tach ... I figured out to just use a magnetic pickup triggered off the 4 bolts on the crank and connect the pickup to a HEI ignition module to generate a pulse signal just like a car would make .
Then should be able to just use a regular car tachometer .

Mag pick up triggered off the four crank bolts.
GM 4 pin HEI module NAPA TP45SB
W= positive lead from the pickup
G= negative lead from the pickup
C= tach lead
B= positive, ign on