The car : 1995 Camaro Z28 LT1
The problem : I bought a harness from a 1995 Pontiac to wire up my engine/tranny after a tranny swap and cam install. I ran the harness and connected all the connectors. Before the initial start up, my buddy hooked up a scan tool. No connection with the PCM. After trying to figure out the problem for some time, we ended up running a wire from the tan wire on the C105 connector seen here:
http://shbox.com/1/harness4.jpg

To the tan wire C220 connector inside the cab. EVERYTHING WORKED FINE.

The connector I am dealing with is the white C220 connector as seen in this picture:
http://shbox.com/1/harness6.jpg

Regarding the wires coming out of that connector and heading to the dash. There are two tan wires. One goes the the Serial data port. Where does the other one go? The tan wire coming from my serial data port and into the C220 connector leads to no-where. There is no wire coming out of the other side.

What I want to do is re-pin the C220 and C105 connector. There are a few wires on the engine side of the C105 connector that are not going anywhere. What are these wires for? I only have one tan wire and one pink wire.

Any help would be appreciated.

 

Here are a few pics to help out the explanation:

Inside the cab. The tan wire coming from the serial data port leads to an empty space.




Engine side of the C105 connector. Only two wires:




Opposite end of the C105 connector. Wires leading to empty spaces everywhere:

 

The harness connector faces link in the schematics section of my Tech Page lists where those wires go.

 

Thanks shoebox. Looking through the pinouts, I got a traction control harness even though I do not have traction control. I still do not understand why I do not have a serial data wire coming through the firewall to the C220 connector. The harness is in great shape and appears to have never been tampered with.