I put a 93 dodge cummins in my 49 Suburban. I have the orginal harness installed, but can't get the tach on my Hinelien gauges to work. Any ideas???

 

the original dodge harness, or suburban harness? The Dodge setup on a 95, which is waht I swapped into my 97 suburban, has 5 volts going to the sensor/pickup at the harmonic balancer. I don't know if that's how they did it in 93, but it wouldn't work with my factory tach. Couple things going on.....1, the Cummins balancer has only 2 notches in it for the sensor to pick up, and the GM dash tach is looking for 4 pulses per revolution. Also, I'm guessing that if the sensor has 5 volts input, that the output might also not be correct for the dash tach.
Now.....I don't know how any of that applies to your Hinelien gauge. I havn't hooked up a tach to mine yet....still trying to figure out how to go. I could machine 2 more notches into my balancer and try it. If push came to shove I could also replace the Dodge sensor with a "Hall effect" sensor of 12volt value. I'm pretty sure that would work because that is how I did my 72 Bronco/4bt tach setup, although it uses an AutoMeter tach.
Others have used a tach sender setup avail from AutoWorld out of Montana. Their setup is a couple hundred bucks though.

 

The 93 harness. I'll check the voltage

 

Does it charge? on a 93 the module has to see a tack signal to turn on the alternater. If you are running the dodge harness, as I am, then the crank position sensor is good or its not charging.Rocky

 

She charges, I didn't know that about the alternator though.