Is this the TSC plug I've read about?

[S_Gibson]

1970 C-10 w/ 3 OTT and no AC.

I have 3 wires that are not connected to anything. 2 tie into a plug that reminds me of an AC clutch plug. Looks like a blue or green w/white stripe and black wire. The other is stripped on the end and looks green.

The green wire appears to go to a relay where there is a red wire running out of the firewall to the relay and a black wire that runs down the firewall toward the bottom of the truck. Was too wet to climb under to see where is goes.

I was temped just to cut it it all out as it appears to not be needed.