What are these wires for?
 

These wires and terminal are on the passenger side of the engine. It's a 71 c10 with a 307. The engine is almost all original with the exception of HEI.

Thank you!


Oh, ignore the fuel filter location - I'm going to take that out before it leaks all over the engine and causes a fire!

Re: What are these wires for?
 

Close up

Re: What are these wires for?
 

Can't think of anything outside to A/C compressor, but mine are a green wire in woven sheath, with a black wire coming off the plug for ground.

Re: What are these wires for?
 

TCS transmission controlled spark

Re: What are these wires for?
 

Thanks! I had never heard of that but now that I know what to search for I see I'm by far not the first to wonder about these wires.

Thanks again!

Re: What are these wires for?
 

HAHA....pretty sure that goes to your alternator.

Re: What are these wires for?
 

I think it's worded transmission spark control or TSC. That plug went to a vacuum deal that controlled the vac advance. I'm fuzzy on an auto but my 4 speed has a switch on the trans that turns advance on when you are in high gear. If yours is non auto you might find a wire coming off trans too There's a vac switch on thermostat housing too that connects. Most are disabled and forgotten anyway

Re: What are these wires for?
 

Alternator is other side on a short pump small block. Wrong colors too. Your alternator will not work very well plugged into there

Re: What are these wires for?
 

Yeah, I think the TSC has been dismantled and discarded at some point. I do have an automatic but I see no remnants of the TSC (or anything to plug this into).

Thanks!

Re: What are these wires for?
 

Little different than my TCS, same year. Mine didn't have the woven sheath, though I suppose it could have been removed. Wouldn't surprise me, because it didn't look right routed through the retainers on the LH valve cover. That and my wires to the solenoid on the carb. were brown, blue, and one brown/white striped.

I won't be connecting the TCS with the rebuild, I hear you're just as well without it. Mine wasn't hooked up anyway and it ran great.

Take note: I'm colored blind, but I try.

Plug to solenoid:
https://scontent-sjc2-1.xx.fbcdn.net...3d&oe=58B41E12

The wires to the solenoid came off this mix. If you can't ID where yours are coming from, couldn't tell you. Perhaps a 307 and/or manual differ:
https://scontent-sjc2-1.xx.fbcdn.net...d4&oe=58F2DBF1