Truck Stays Running With Key off.

Yep, qualitytruck is right. The main causes for a truck staying on with the key in the off position are
1. The PDM (fuse box) on the left side behind the seat could be shorted out. Disconnect the black and gray connectors on the top of the PDM
2. If you have an old company truck, check to to see if there is a qualcomm cable above the cab. They have all time power and ign wires that corrode and cause a short
3. Sometimes the I terminal on the alternator will cause a short in the vigil light bar, and will cause the ign circuit to stay powered up. That is the least likely issue though.

 

Ok guys problem solved, it turned out to be one of the two relays that's on the passenger side knee area, It was toasted. The shop guy also removed the pdm fuse box on the driver side door area and cleaned the harness, now the truck shuts down on command, and also all the dome lights and cigarette ports work. Total cost was 130$ for parts and labor. Fyda freightliner wanted me to replace the computer (1300$ alone) and charge me about 5hrs of labor and reprogramming the new computer. They can go to Hell. Well thanks everyone.

 

Freightliner will have you replacing parts you never heard abour. They'll say crap like you need a new air freshener to match the one in the sleeper and once they replace that they hope that fixes the problem. Oh and if it doesn't they'll try and sell you some more crap.

Glad u got it figured out for a great price

 

Does this also applies for a 2012 cascadia isx?
My dash is not responding at all

Thank you

 

My 2012 cascadia with isx has the same problem and now dash is completely unresponsive.
Any help appreciated.

Thank you

 

Look for the wires around steering column, there’s a short somewhere around there, had the same issue years ago on a 2008 Cascadia would keep on running with a key out of the ignition. To shot the truck off put it in a higher gear 8 or 9 breaks on a truck and trailer applied yellow and red knob pulled out and release the clutch until the engine dies.

 

what’s the name of this fuse box , I am having same problem

 

It happens.

That's trucking.

 

You have the name in the quote. Auxillary PDM (power distribution module)