Red/Yellow stripe wire?

[High Pressure]

I have reviewed the electrical drawings in the Tech section. Don't seem to be able to find electrical schematics for a '77 C4 auto (or other years). I have a Red/Yellow stripe wire that passes throught the fire wall at the same location as the 4 wires for the C4 auto. It does not go into the 4 pin connector for that runs down to the C4 (all 4 wires present).

Any ideas what it is for?

 

[70_Steve]

I looked through the schematics on N8's Site, and found several Red w/Yellow wires. The only one I could find that would pass through the firewall is for the Carburator Valve Control Solenoid.
http://www.wsu.edu:8080/~i6735189/75_77wd2.gif

 

[Viperwolf1]

Headlight switch to headlight dimmer switch wire is red w/yellow stripe (wire # 15) but it shouldn't go through the firewall. The carb valve control solenoid wire (# 640) is actually red w/ yellow hash and does go through the firewall.

 

[Thomas H.]

Headlight switch to headlight dimmer switch wire is red w/yellow stripe (wire # 15) but it shouldn't go through the firewall. The carb valve control solenoid wire (# 640) is actually red w/ yellow hash and does go through the firewall.

X2 this is correct