Where does this wire belong? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**SOUTHERN917** · 12-13-2008, 07:24 PM

I replaced my timing chain,oil pan gasket, etc. this weekend, and while replacing fly wheel cover I noticed a small lt. green wire with a round rubber boot hanging down on pass. side of tranny. There is so much oil and dirt covering this area I thought I'd ask where exactly this plugs in, if I need it (it has been out for a long time by apperances), and what is it? BTW it's a TH350.

**WorkinLonghorn** · 12-13-2008, 07:50 PM

Sounds like the TCS or transmission controlled spark. I believe there was a switch on the trans. with one wire going to it. The system was an early attempt at emisions improvement. In lower gears you would not get any distrib vac advance,and lots of folks disconnected this system.

**SOUTHERN917** · 12-13-2008, 08:13 PM

Thanks, I'll live without it!

OhioDan · 12-14-2008, 05:27 AM

Sounds like back-up light wire for the 4 spd. trans?

JimKshortstep4x4 · 12-14-2008, 06:54 AM

The four speed back up light had two larger wires to it (one light green/one dark green). The back up wiring for the four speed also routed up from the passenger's side of the transmission.

The small green wire is more than likely what WorkinLonghorn said.

Jim

**SOUTHERN917** · 12-14-2008, 09:22 AM

I have back up lights, and it is caked with dirt/oil so I know it's been out of service for a while. Thanks for the responses.

Wrenchbender Ret · 12-14-2008, 10:57 AM

Could it have had a TH 400 at one time? They had an electrical kickdown with a connecter like that. It also may have gone to an oil pressure light. Sometimes it falls down from the back of the engine & apears to go to the trans.

**SOUTHERN917** · 12-14-2008, 02:53 PM

It has always had the th350. It was a 2 owner, Father then son, then me. They kept every scrap of paper/receipt/oil change etc. for 40 years. It sat for almost 3 years before I convinced him that I would take care of it and bring it back to life if he would sell it to me. He almost cried when I picked him up for that first ride after I got her going.

dwcsr · 12-14-2008, 02:59 PM

Workinglonghorn is correct its part of the old emissions system. That switch operated under pressure from the trans and controlled spark advance and it often leaked. I removed mine and pluged it.

**SOUTHERN917** · 12-14-2008, 06:09 PM

Does anyone have a pic of this area? I want to make sure the hole is plugged.

mikeoj · 12-14-2008, 06:25 PM

This may help,http://67-72chevytrucks.com/vboard/s...iring+diagrams Will take a minute or so to load!

68caliRat · 12-14-2008, 07:31 PM

Quote:

Originally Posted by mikeoj

This may help,http://www.boomspeed.com/bofh1968?ch...ng_diagram.pdf Will take a minute or so to load!

[quote]WHAT ARE YOU DOING SNOOPING AROUND MY HOSTING???? [/quote.]

mikeoj · 12-14-2008, 07:49 PM

I have corrected the link,sorry.

12-13-2008, 07:24 PM	#1
SOUTHERN917 Wrench Wench Join Date: Apr 2008 Location: HERRIN, IL Posts: 93	Where does this wire belong? I replaced my timing chain,oil pan gasket, etc. this weekend, and while replacing fly wheel cover I noticed a small lt. green wire with a round rubber boot hanging down on pass. side of tranny. There is so much oil and dirt covering this area I thought I'd ask where exactly this plugs in, if I need it (it has been out for a long time by apperances), and what is it? BTW it's a TH350. __________________ If everyone had good taste, who would buy all the FORDS? Women join us!! BUSTED KNUCKLE BABES "Face it girls, I'm older and have better insurance" -Fried green tomatoes Last edited by SOUTHERN917; 12-13-2008 at 07:34 PM. Reason: left somthing out

12-13-2008, 07:50 PM	#2
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,861	Re: Where does this wire belong? Sounds like the TCS or transmission controlled spark. I believe there was a switch on the trans. with one wire going to it. The system was an early attempt at emisions improvement. In lower gears you would not get any distrib vac advance,and lots of folks disconnected this system. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, 2nd owner, Work-Truck supreme. Best $300 I ever spent.

12-13-2008, 08:13 PM	#3
SOUTHERN917 Wrench Wench Join Date: Apr 2008 Location: HERRIN, IL Posts: 93	Re: Where does this wire belong? Thanks, I'll live without it! __________________ If everyone had good taste, who would buy all the FORDS? Women join us!! BUSTED KNUCKLE BABES "Face it girls, I'm older and have better insurance" -Fried green tomatoes

12-14-2008, 05:27 AM	#4
OhioDan Registered User Join Date: Apr 2002 Location: New Carlisle, Ohio,USA Posts: 1,404	Re: Where does this wire belong? Sounds like back-up light wire for the 4 spd. trans? __________________ LIFE AIN'T EASY WHEN YER FAT AND GREASY! GMC= Got More Class! 1970 GMC LWB, Fleetside, 350/4spd, Flowmaster "40's", 2002 GMC 16" Rallies, cowl hood,and added a bunch of options that weren't there when I started.

12-14-2008, 06:54 AM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Where does this wire belong? The four speed back up light had two larger wires to it (one light green/one dark green). The back up wiring for the four speed also routed up from the passenger's side of the transmission. The small green wire is more than likely what WorkinLonghorn said. 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 Last edited by JimKshortstep4x4; 12-14-2008 at 06:55 AM. Reason: spelling

12-14-2008, 09:22 AM	#6
SOUTHERN917 Wrench Wench Join Date: Apr 2008 Location: HERRIN, IL Posts: 93	Re: Where does this wire belong? I have back up lights, and it is caked with dirt/oil so I know it's been out of service for a while. Thanks for the responses. __________________ If everyone had good taste, who would buy all the FORDS? Women join us!! BUSTED KNUCKLE BABES "Face it girls, I'm older and have better insurance" -Fried green tomatoes

12-14-2008, 10:57 AM	#7
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,208	Re: Where does this wire belong? Could it have had a TH 400 at one time? They had an electrical kickdown with a connecter like that. It also may have gone to an oil pressure light. Sometimes it falls down from the back of the engine & apears to go to the trans.

12-14-2008, 02:53 PM	#8
SOUTHERN917 Wrench Wench Join Date: Apr 2008 Location: HERRIN, IL Posts: 93	Re: Where does this wire belong? It has always had the th350. It was a 2 owner, Father then son, then me. They kept every scrap of paper/receipt/oil change etc. for 40 years. It sat for almost 3 years before I convinced him that I would take care of it and bring it back to life if he would sell it to me. He almost cried when I picked him up for that first ride after I got her going. __________________ If everyone had good taste, who would buy all the FORDS? Women join us!! BUSTED KNUCKLE BABES "Face it girls, I'm older and have better insurance" -Fried green tomatoes

12-14-2008, 02:59 PM	#9
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,134	Re: Where does this wire belong? Workinglonghorn is correct its part of the old emissions system. That switch operated under pressure from the trans and controlled spark advance and it often leaked. I removed mine and pluged it. Last edited by dwcsr; 12-14-2008 at 03:00 PM.

12-14-2008, 06:09 PM	#10
SOUTHERN917 Wrench Wench Join Date: Apr 2008 Location: HERRIN, IL Posts: 93	Re: Where does this wire belong? Does anyone have a pic of this area? I want to make sure the hole is plugged. __________________ If everyone had good taste, who would buy all the FORDS? Women join us!! BUSTED KNUCKLE BABES "Face it girls, I'm older and have better insurance" -Fried green tomatoes

12-14-2008, 06:25 PM	#11
mikeoj Senior Member Join Date: Nov 2000 Location: WI,USA Posts: 495	Re: Where does this wire belong? This may help,http://67-72chevytrucks.com/vboard/s...iring+diagrams Will take a minute or so to load! __________________ 69 Lwb C-10 402/700R4 70 Lwb C-10 250/3pd Wisc. Last edited by mikeoj; 12-14-2008 at 07:47 PM. Reason: wrong info

12-14-2008, 07:49 PM	#13
mikeoj Senior Member Join Date: Nov 2000 Location: WI,USA Posts: 495	Re: Where does this wire belong? I have corrected the link,sorry. __________________ 69 Lwb C-10 402/700R4 70 Lwb C-10 250/3pd Wisc.



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