What are these wires for? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ctsandb · 12-05-2016, 10:38 PM

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!

ctsandb · 12-05-2016, 10:39 PM

Close up

**71CHEVYSHORTBED402** · 12-05-2016, 11:09 PM

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.

60case · 12-05-2016, 11:19 PM

TCS transmission controlled spark

ctsandb · 12-05-2016, 11:31 PM

Quote:

Originally Posted by 60case

TCS transmission controlled spark

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!

**Dustmaker65** · 12-06-2016, 01:56 AM

Quote:

Originally Posted by 60case

TCS transmission controlled spark

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

Gmc.guy · 12-06-2016, 10:03 AM

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

Gmc.guy · 12-06-2016, 10:05 AM

Quote:

Originally Posted by Dustmaker65

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

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

ctsandb · 12-06-2016, 11:23 AM

Quote:

Originally Posted by Gmc.guy

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

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!

**71CHEVYSHORTBED402** · 12-07-2016, 01:07 AM

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:

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:

12-05-2016, 10:38 PM	#1
ctsandb Registered User Join Date: May 2006 Location: Berea, KY Posts: 70	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! Attached Images __________________ Curtis - Berea, KY 1969 1/2 ton 2WD CST 1971 1/2 ton 2WD Shortbed 1977 Mercedes 450SL 1966 International Scout

12-05-2016, 10:39 PM	#2
ctsandb Registered User Join Date: May 2006 Location: Berea, KY Posts: 70	Re: What are these wires for? Close up Attached Images __________________ Curtis - Berea, KY 1969 1/2 ton 2WD CST 1971 1/2 ton 2WD Shortbed 1977 Mercedes 450SL 1966 International Scout

12-05-2016, 11:09 PM	#3
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,129	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. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s details such as OEM identifications& part numbers, written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

12-05-2016, 11:19 PM	#4
60case Registered User Join Date: Feb 2015 Location: friendship WI Posts: 173	Re: What are these wires for? TCS transmission controlled spark

12-06-2016, 10:03 AM	#7
Gmc.guy Registered User Join Date: Nov 2015 Location: Alberta Posts: 464	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 __________________ -Cody

12-07-2016, 01:07 AM	#10
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,129	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: 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: __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s details such as OEM identifications& part numbers, written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 12-10-2016 at 12:43 AM.



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