CD Player installation in Jeep Grand Cherokee

My daughter had a Sony CD player stolen from her Jeep. The insurance company has furnished a new Pioneer as a replacement. I have it all wired up, but it refuses to light up and/or play. There is one left over wire in her dash that has no counterpart in the wiring harness of the new CD player. It is blue with a red trace. It is not hot with the key turned on. Unfortunately, since an amatuer was responsible for the removal, I have no way of knowing what that wire was hooked to on the stolen Sony.



Any ideas?



TIA

The factory wiring for the “radio” is shown at the following website: http://search.ebscohost.com. User ID = user, Password = password, click Login. Scroll downn to Auto Repair Reference Center and click. Enter vehicle year, make, model, engine and submodel. Click on Witing Diagrams. Click on Sound Systems. Read sound system wiring diagrams.

Now that was incredibly neat. The wire in question appears to be the source for a light as it comes from the parking light relay. I suspect that this CD player has its own light, and that this wire is unnecessary for that purpose.

Ground is good. Hot wires with key on and for memory are both hot. Speaker wires all agree with the printed instructions by color.

So why doesn’t it work?

If the power to the unit checks out ok but there are no signs of power on the unit then there may be a problem with the new unit internally. If the unit shows signs of power but no sound then there may be an external amp that needs to see power coming from the new unit to turn the amp on.

As it turned out, the ‘always hot’ wire apparently had blown a fuse after I checked it. I suspect it came in contact with the antenna’s ground. Yup, I should have disconnected the battery, just like the directions said. The fuse was not labled as having anything to do with the CD unit, but replacing it made it all work as advertised.

Now, wasn’t that fun? Wasn’t it made even funner with the use of the wiring diagram? By the by, what year and sub-model is this Grand Cherokee? Which fuse was it, and is all ways hot? The #17 “Park Lamp” fuse? Or, the #20 fuse (what name?)?