Ok so a few years ago I added in an overhead console with compass/ temp. Everything worked but one thing I could never find was the VSS to hook up to. I have a Class 2 DATA Type Radio with 24 pin connector.

No problem, it worked without it.

Now I upgraded to the DIC with mpg etc. Added the 2 wires in. It powers up, lights up and dims properly. However only the compass works the rest is just "--".
I have read everywhere I need to hook up the VSS to pin 16 on radio but I have no pin 16 nor a green/white wire. Here is a breakdown of my connector;

2002-2004 Blazer
•12v Ignition = Pin# B2 = Dk.Green (RAP)
•12v Constant = Pin# B1 = Orange
•Ground 1 = Pin# B5 = Black
•Ground 2 = Pin# A12 = Black
•Illumination = Pin# B4 = Gray
•Dimmer(LED) = Pin# B12 = Purple/White
•Serial Data = Pin# A1 = Gray
•Steering Cont = Pin# A7 = Dk.Blue
•LF Speaker + = Pin# A8 = Tan
•LF Speaker - = Pin# A9 = Gray
•RF Speaker + = Pin# B11 = Lt.Green
•RF Speaker - = Pin# B10 = Dk.Green
•LR Speaker + = Pin# B8 = Brown
•LR Speaker - = Pin# B9 = Yellow
•RR Speaker + = Pin# A11 = Dk.Blue
•RR Speaker - = Pin# A10 = Lt.Blue

Note there is a Serial Data wire at A1.

So where could I find a VSS wire to tap into, or do I need to hook to the Serial Data wire? (I'm thinking no). Any help appreciated.