Hey feller's!

i have a 02 5.9 running like a top in standalone config. I also have a healthy tach pulse coming from the ecm. My Glowshift Tach on the otherhand isn't picking up the signal. Does anyone have experience with aftermarket Tachs running off the ECM? Do i need to put a resistor inline with the B+ to step down the current or somthing? Also does the field generator wire need to be grounded and the system voltage hooked to Key On power for the ecm to regulate the alternator? It appears to be charging but can't confirm that its the proper way to rig it up.

Thanks!