Cummins Wiring Interface

[C20scott]

Auto Transmission electronic controls are way above my head.

You can start the 12 valve with fuel, 12v to the starter, and manually hold the fuel shutoff lever up. I apologize if you are already aware of how simple the electronics are in these. As far as aftermarket gauges. See below.

Temp sending: Same as chevy, just adapt an electronic sending unit in the place of the cummins one, or at the spare opening at the t-stat housing. might be a separate size sender porthole.

Volt: same as chevy, connect to alt/battery circuit

Oil Pressure: Same as chevy, i used electronic sender in place of cummins one near oil filter.

Fuel: same as chevy, match the sender Ohms that you are using

Speed: Same as chevy, match to senter at tailhousing of trans or Tcase

Tach: This is the only one that get complicated. The cummins has no "ignition" like a gasser that sends off of distributor pulses. you will need to get an RPM reading either from the alternator or the rotating assembly. The easiest way in my opinion was to use the cummins RPM senser, and hotwire it to send a RPM pulse to the tach, basically fooling the chevy tach into thinking its getting an RPM signal. Let me know if you want more info. Basically using a radio shack resistor in the tach wiring.

EGT: this is an extra that you should have. I bought a digital EGT gauge, sender just threads into a tapped hole in the exhaust manifold

Boost: this is an extra that you should have. I boght a matching digital, sender taps into intercooler piping.

Trans Temp: you should have this towing with auto, but above my head.

Pics of mine for reference to gauges that i made work. Oil, Temp, Fuel, Volt, speed-VDO Tach, boost, egt-Autometer