DodgemnLeavem

truck in sig. turn on key get nada sometime start but then will shut off while driving, sometimes will get back on but not without effort. no dash lights when goes off while driving. No Codes. Replaced ignition switch with no help. What could be causing this? TIPM? ECU? PCM? FCM? I can hotwire the truck (jumper wires on ignition switch plug)and will run and drive but (abs lights brake lights all remain on) heater controls wont work, speedomoter wont work no reverse lights what could be causing this. About to take to *********** on monday but trying to avoid that can anyone help. ?.

07 ThunderRoad

This is out of left field, but the dealer mechanic told me tha they have had the com buss drop below 2v on the ODBll. This will not allow the modules to talk to each other. I know this sounds crazy but they traced one trucks problem to the trailer connector at rear bumper shorting out thru corroded connector terminals. Same problem, you can make the Cummins engine run, but all other systems are down or in a warning state. Any break, or short to body, in the com buss wiring will cause this. Also any bad controller, connector that the comm buss passes thru, ect,ect. Electrical problems are the leading cause of death to a good truck.

FMB

There was an issue with a wire rubbing behind the AC compressor that eventually grounded out and caused issues. Search for that here.

DodgemnLeavem

thats out there alright..lol makes sense though
Im Not so sure thats the prob here, but anyways, heres what happend I unhooked the batteries and figured Id reset everything while installing my Hid lights, all goes well rehook batteries reset apps, and then fire it up,
WAAHHOOOO I can see now! after some fine adjustments of the headlights (its dark) its always dark in the winter here LOL... and drive home, all goes well then all the sudden it just shuts off, no dash lights nothing only things on are the headlights and tail, but no turn sig not even heater,or radio. I pull to side of the road and try to figure it out, yup battery cables are tight,,but nothing,, then after pressing the brake peddle and trying the key and other things it starts. Ok just a hickup,Ill give it one, well next morning now it wont do anything, well I try the Auto start and it starts,hmmm well the way its hooked up only thing that works is the heater and of course the lights, but soon as I hit the brake it dies (its supposed) ok hmm ignition not working, well I replace it and still the same so then I figure ok darn you your gonna RUN so I unhook the plug from the key switch and hot wire it,, well a jumper here a jumper there and vola its running at first I didnt have everything working but I jumped another wire combo and Now??!!!

everything works like factory. didnt know it was so easy to hotwire a dodge cummins, I can even read codes. and there was but one Intermitant ecm power or something cant remember now, but what gives everything is working right now,, well hot wired that is, but if I hook upto the new key switch nothing happens or maybe it does. I cant figure but that there is a power module gone bad ..

sorry long post

DodgemnLeavem

now that you mention that I remember reading about that Ill recheck that But If I recall my truck was one of them that had it Rerouted so asto not be a issue, when I checked it.
but hey thanx man