You likely do not have a cord. It comes standard only in a few states. If you can find the window sticker take a look to see if the previous owner order it. It they did then it will be around the passenger side tow hook. If it does not have the cord then you will need to install one yourself. You can get the cord from any heavy truck shop or off ebay. The one for the dodge cummins will fix the psd just fine.
Diesel Technician Society
change all fluids and filters.... enjoy and take good care of it.