Cm 870 turbo actuator control module

[Slappy]

To start over. 07 international 9400 with a 06 cm870. Truck is completely factory, set at 475 hp with all systems operating and no modifications. Truck has ran great for the most part with exception to cleaning some egr stuff through the years. Driving along truck would drop voltage from 13.8 to 12 and less,cough out a huge plume of smoke til the volts climbed back up and run fine. It’s done this a few times the past month but would be intermittent and run fine after. However two or so weeks ago running along interstate empty it started to loose voltage then return to normal constantly but then the turbo control box started popping off air making me think it was it causing problems. Put a new reman turbo box on and same thing,tried another good used box and same. Use to be intermittent but now is constant even at idle. Thought it maybe egr valve and pulled plug but no change. Truck hasn’t thrown any codes for anything . I’ve been tearing apart wire harness and found 1 small rub through but it didn’t change anything. Something is not right and I’m pulling my hair out. I checked the wiring for turbo control box leads and it shares a ground with the pick up fuel pump which is all good so it’s not that. Something has to crossings over somewhere that effects that circuit along with egr circuit is my guess…only a guess which is terrible.