This sounds like a CAN BUS style truck in which the computer controls the radio.  Unlike standard vehicle applications wher you could buy a interface part to get back the issues, no such parts is available for the semi.  If that is all you lost that might be okay based on the only way to fix.  The fix is a Can Bus radio.  JCV2015BT plugs into the truck and maintains all your features.  Watch the video and see what is   Read more...

Look at this page 2nd from the bottom and we have a plug that should plug into the delphi.  It will run the speakers and power the unit through the   Read more...

You didn't give the year of the trucks but if both are newer than 2005 the plus are the   Read more...

YES, likely those are the speaker   Read more...

Not realoly a harness for that.  What you need is called a Preamp adaptor.  This device will hook to the rear speaker outputs by scotch locks or what ever means you can do to give you a preamp feed off the rear leds.  Trigger the amp with ingition wire and you are done. Check Crutchfield for the PREAMP adaptor.  Purchase one that can handle the radio pre channel power.  Usually a 25watt version will   Read more...