Dodge Repair: 04 Durango: Radio Not Working

Question
I have a 2004 Dodge Durango with the infinity speakers, a 6 CD Changer internal AM/FM Radio.  The unit will not come on.  I have checked the fuse and it is good, unplugged and reconneted the unit, and I still have no power to the unit.  I was informed that the unit must be bad so I purchased a unit and installed it.  Still no power to the unit.  What should I do next.  Can not afford a trip to the dodge manufacture.

Answer
Hi John,
It is possible that the fuse looks good but has a subtle crack in its internal wire, so look at that fuse #12 (25 amp) in the fuse box in the cabin very carefully. Try substituting another 25 amp fuse for it.
Do you have a volt-ohm meter? If so you could check the fuse for continuity measuring that there is a connection between the two ends using the ohm meter. Also, the fuse's socket (at one end) is connected to the battery so the fuse should show 12V on both ends compared to ground. The other thing to do is to check the two pins on the multi-pin plug found at the back of the radio where the voltage coming from fuse 12 should be present at all times: specifically pin # 1 and # 12 of the 22-pin gray color plug. Also verify that the ground wires on pin # 11 and #22 of that same plug show connection to ground (any nearby metal that is part of the chassis; resistance reading should be near 0 ohms if connected). Alternatively, go to the place where those ground wires are attached to the body which is a clip that is screwed into the body ( located just in front of the passenger side door opening, on the "kick pane" about a foot above the floor and verify that it is tight.
I don't see any other reason why the radio shouldn't exhibit some "life" if those four pins on the 22-pin plug are as I suggest they should be. Let me know what you find.
Please read the PS (below) and respond to it.
Thanks,
Roland