How to Install Factory CD Changer if 3 Wire Plug is Missing

T
his information came from Alan Barbic (California Quicksilver)
I
also went through the same frustration in the \”great search\” for the
elusive three wired connector. You are not delusional.. It was not in my
98 vert either. I went over the wiring diagrams in the factory service
manuals and was able to establish the role our elusive three wires play in
the equation. I resolved the problem by thinking a bit out of the box (see
how below) and now have a flawless trouble free install.
To start clip
the three wire plug off the new CD wire harness (you will play hell trying
to find its mate anywhere so you might as well get rid of them) and
install male bullet type connectors on each of the three wires.
Now prepare three sections of wire (14-16 guage) at about 8 inches
each and crimp and/or solder the appropriate female connectors needed to
go with the newly attached males on the CD harness.
Now we go
looking for the connection points for the three newly made sections of 8
inch wire.
All of these will be found in or close to the big \”wad\”
of wires in the R/H upper portion of your second photo seen at;

http://temp.corvetteforum.net/c5/rpoz4z//mvc-011s.jpg

You will need a
meter preferably one that has a squawk feature when doing continuity
checks and sharp probes that allow penetration through wire insulation.
Three wire Signal CD/Radio connection
1)SW +12 out C1(8) DK
GRN, Radio \”ON\” signal
2)Power C1(10) ORG (always hot
??)
3)ground C1(5) BLK/WHT
Starting with the easiest 3)ground =
BLK/WHT You will find this one every where and any one will work just test
continuity from wire to chasis ground and solder one of the 8 inchers to
it.
Next is 2) ORG = hot (I am fairly sure it is always hot) This
one is in that \”wad\” of wires above the fuse panel in the photo.
Current test by putting one lead to chasis ground and probing the other
lead to the same color orange as the CD harness orange untill you get
12+/- volts (note:the radio fuse is also part of this wire so you can test
from there however the test then turns into a continuity test first and
then a 12 volt circuit test after you have identified you orange in the
\”wad\” )
then solder up that one.
The last one is a lot more
of a challenge 1) Radio signal = DRK/GRN There are several shades of green
so again use the CD wire harness as a color guide in the search. This
color seems to be used as a communication link for several componants in
the system so you will see this color wire used a lot in that \”wad\” of
wires but only one or two of them are the ones you need. The way to find
the wires in question is to pull the fuse panel and remove the box from
the firewall (don\’t disconnect any wires). In the back of the box about
midway are two of the dark green wires that are together put a probe on
one of them and do a continuity search at the \”wad\” for it. When you
find it strip a bit if the insulation away and connect the last 8 incher
to it (DON\’T SOLDER YET) now actually connect up all three wires and
fire everything up with CD\’s in the 12 disk cartridge. If it is not
working (the unit will take and shuffle the CD\’s but no music) then you
tapped into the wrong Dark Green wire so keep tapping untill you found the
one that enables the system and then solder it up.
All should now work
as intended so go ahead and finish up the install.
Now all there is to
do is enjoy.