68 C10 Yellow wire from firewall to starter/coil.

[C10CORIE]

So I have a HEI and a BBC in a 1968 C10.

I have a wire running to the HEI that is wired into a 12V "key on" hot panel.

There is a wire that runs fron the top 1/2 of the outside firewall plug, which is supposed to be the YELLOW wire the goes to the starter/coil.

My question to you wiring guru's is...............what is the purpose of this wire and do I need it if I have a wire run to my HEI ignition????


Thanks in advance

Corie.