cummins code 431

Here it goes guys I've been troubleshooting a code 431 on a cummins idle validation switch here's what I've done I've replaced potentiometer and harness one new and one good used setup I've swapped ecm with a know good one I've pulled the oem harness and inspected and replaced all the wires from ecm to gannon plug on the firewall problem still persisted intermittent check engine lite and idle only tap the throttle and it goes away then comes back when you gently push the throttle so I ended up finding the wires in the cab and bypassing them still did the same so I put in a another new potentiometer calibrated it and now its all good so here's the question one been working on this project off and on for a few weeks when I get a chance I think there's a short in cab harness do you think it could have shorted out the other potentiometers or am I crazy this is one of those projects that maked you bang your head on the wall so what so you guys think any experiences you've had with some electrical gremlins will help thanks guys

 

Cummins ism

 

Already did multiple times with diffrent harness and potentiometer same problem opens oem harness replaced all wires same thing bypass wires under dash same code with same potentiometers put a new one recalibrate and now its all good so I'm thinking I have. A short in the dash harness and its damaging the potentiometers I tried 2 new ones and 2 used ones that were good any thoughts all I know is it seems fixed so I'm sending it back to work