Hi, on a 91.5 auto 4x4, if I want to do an ECM delete -
1/ Grid heaters - momentary on pushbutton switch - blue wires from heater relays grounded via the switch
2/ TPS - shouldn't make a difference as all it does it set the 3rd to 4th shift point
3/ OD - red wire off the OD solenoid grounded through a 2-pin toggle switch
4/ Speedo - blue wire off the VSS grounded to chassis
5/ Rear ABS - not affected if I unplug the module
6/ Charging - not affected, as 91.5 is regulated externally
7/ AC & cruise - don't have these on my truck
8/ KSB - not sure what the will affect
9/ Fuel heater & water in sensor - use the Cummins delete nipple and go with an integral drain Fleetguard FS1221 or similar)
10/ The FSO shouldn't be affected
The coolant temp switch, trans temp switch and air temp switch can be left connected as they are now redundant
With the harness unplugged at the ECM, the truck starts, runs & turns off just fine, except that the grid heaters and OD don't get a closed ground circuit.
Anything else Im missing?