1970 C/10 Electrical Issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

etravis46 · 08-01-2009, 05:03 PM

Ok. So I usually try to answer all my questions by researching past threads and searching the internet but I can't seem to find any info that can help me. I have a 1970 C/10 CST longbed. I bought it in Feb and it had a V8 with a two barrel on it. Manual steering and manual brakes. I checked the Serial on the engine and I believe it is a '73. So I am pretty sure someone has swapped engines in the past. I found a 75 c10 for 300 bucks and pulled the engine, rotors, and power steering off of it. I have already finished the disc brake conversion and added power brakes as well as the power steering.

Then I get to the engine swap. The '75 has been rebuilt fairly recently and has an Edelbrock carb with electric choke and an HEI. The old engine that was in my '70 had a points system and and externally regulated alternator. So I start tearing into things and all goes smoothly until I realize I have some wires that I can't remember what they go to. I've checked all of the diagrams I can find and can't seem to make sense of them.

So my first question is what is this connection block called in the first picture and does it do anything or just serve as a junction point.

Second question is does anyone recognize this black plug connector. It goes to the flat connector that has the black and blue wire. I originally thought the black and blue wires went to my alternator because it fits the slot but after researching I just don't know.

Since I am asking questions, I'll also ask if anyone recognizes the large pink wire in the third picture. I believe it goes all the way back to the ignition switch.

I know electrical questions are tough because colors fade and/or have been changed in the last 40 yrs by who knows who but I hope someone can help me out! Thanks!

fixit-p · 08-01-2009, 05:12 PM

Pic #3 pink looks like power wire for electric kick down check for power with key on.

JimKshortstep4x4 · 08-01-2009, 06:48 PM

Pics 1 and 2 look like part of a TCS system. The black plug looks like the plug for the tranny which was tied into the TCS system. The system is extraneous to the trucks wiring and have been eliminated by some.

Pic 3, the heavy #10 wire has the right end on it to plug into an HEI but it too was probably part of the system. The green wire in pic three is for the temp gauge or it could also be part of the TCS wiring. The green color is a little off to be a temp gauge wire but it is hard to tell because of the fading.

Jim

08-01-2009, 05:03 PM	#1
etravis46 Registered User Join Date: Mar 2009 Location: White House, TN Posts: 12	1970 C/10 Electrical Issues Ok. So I usually try to answer all my questions by researching past threads and searching the internet but I can't seem to find any info that can help me. I have a 1970 C/10 CST longbed. I bought it in Feb and it had a V8 with a two barrel on it. Manual steering and manual brakes. I checked the Serial on the engine and I believe it is a '73. So I am pretty sure someone has swapped engines in the past. I found a 75 c10 for 300 bucks and pulled the engine, rotors, and power steering off of it. I have already finished the disc brake conversion and added power brakes as well as the power steering. Then I get to the engine swap. The '75 has been rebuilt fairly recently and has an Edelbrock carb with electric choke and an HEI. The old engine that was in my '70 had a points system and and externally regulated alternator. So I start tearing into things and all goes smoothly until I realize I have some wires that I can't remember what they go to. I've checked all of the diagrams I can find and can't seem to make sense of them. So my first question is what is this connection block called in the first picture and does it do anything or just serve as a junction point. Second question is does anyone recognize this black plug connector. It goes to the flat connector that has the black and blue wire. I originally thought the black and blue wires went to my alternator because it fits the slot but after researching I just don't know. Since I am asking questions, I'll also ask if anyone recognizes the large pink wire in the third picture. I believe it goes all the way back to the ignition switch. I know electrical questions are tough because colors fade and/or have been changed in the last 40 yrs by who knows who but I hope someone can help me out! Thanks! Attached Images Last edited by etravis46; 08-01-2009 at 05:16 PM.

08-01-2009, 06:48 PM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: 1970 C/10 Electrical Issues Pics 1 and 2 look like part of a TCS system. The black plug looks like the plug for the tranny which was tied into the TCS system. The system is extraneous to the trucks wiring and have been eliminated by some. Pic 3, the heavy #10 wire has the right end on it to plug into an HEI but it too was probably part of the system. The green wire in pic three is for the temp gauge or it could also be part of the TCS wiring. The green color is a little off to be a temp gauge wire but it is hard to tell because of the fading. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC



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