The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 05-27-2014, 08:23 PM   #1
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Black wire to trans, what is this?

What is this black wire to the trans for, it's a three on the tree 1972 Custom/10 with a 250 i6Name:  image.jpg
Views: 358
Size:  39.5 KB
Custom/Ten is offline   Reply With Quote
Old 05-27-2014, 08:24 PM   #2
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

Name:  image.jpg
Views: 275
Size:  40.4 KB
Custom/Ten is offline   Reply With Quote
Old 05-27-2014, 08:25 PM   #3
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

It goes to here,Name:  image.jpg
Views: 253
Size:  43.4 KB
Custom/Ten is offline   Reply With Quote
Old 05-27-2014, 09:26 PM   #4
425HP409
425hp409
 
425HP409's Avatar
 
Join Date: Oct 2008
Location: Prosper Texas
Posts: 841
Re: Black wire to trans, what is this?

It should be for the backup light switch.
__________________
Charles
68 SWB, Dad bought new, now 396 & factory ac
64 Impala SS, 409 425HP, 4 speed AC
64 Bel Air Wagon, 400 Small Block
57 Bel Air all original 283 w/Factory Air
77 GMC Sprint, 454/425HP
67 Olds 442, all original
90 ZR1 Corvette
425HP409 is offline   Reply With Quote
Old 05-27-2014, 10:47 PM   #5
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

Ok thanks 425HP409 ill go out tomarrow and pull that plug and see if the backup lights stop working.
Custom/Ten is offline   Reply With Quote
Old 05-27-2014, 10:57 PM   #6
ray_mcavoy
Registered User
 
Join Date: Nov 2009
Location: Sherman, ME
Posts: 2,359
Re: Black wire to trans, what is this?

Quote:
Originally Posted by Custom/Ten View Post
What is this black wire to the trans for, it's a three on the tree 1972 Custom/10 with a 250 i6Attachment 1259309
I believe that black wire connecting to the transmission is for the TCS (Transmission Controlled Spark) emissions system.

The backup light switch for the 3 on the tree is located on the steering column and has 2 wires (light & dark green).
ray_mcavoy is offline   Reply With Quote
Old 05-28-2014, 12:22 PM   #7
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

Yea maybe that is a TCS relay in the second picture. All I have seen before are inside the cab above the horn relay though, not here.
Custom/Ten is offline   Reply With Quote
Old 05-28-2014, 01:39 PM   #8
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,622
Re: Black wire to trans, what is this?

The switch on the tranny that the black wire hooks to is the ground switch.
When you shift to third a lobe on the shifter shaft contacts the switch and the tcs is grounded thru the tranny.
geezer#99 is online now   Reply With Quote
Old 05-28-2014, 01:46 PM   #9
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

I'm gonna see if I can find a wiring diagram for TCS. Maybe I can fix it. Right now the blue and brown/white wire are hooked up to nothing.

Last edited by Custom/Ten; 05-28-2014 at 01:58 PM.
Custom/Ten is offline   Reply With Quote
Old 05-28-2014, 01:58 PM   #10
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,622
Re: Black wire to trans, what is this?

Do what ever you like. Hooked up hurts nothing. No power to the relay so you don't need it grounded. It's all just along for the ride.
You can't remove that switch on the tranny though. IIRC it's an odd ball thread size so a normal plug won't fit.
geezer#99 is online now   Reply With Quote
Old 05-28-2014, 02:00 PM   #11
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

Ok thanks geezer
Custom/Ten is offline   Reply With Quote
Old 05-28-2014, 07:48 PM   #12
Custom/Ten
Registered User
 
Custom/Ten's Avatar
 
Join Date: May 2014
Location: Mobile, AL
Posts: 422
Re: Black wire to trans, what is this?

Yea, it's definitely the wire for the TCS sensor. I like a clean look so i removed the wires and relay and got rid of everything but the sensor and the black cap on it. Then I spent an hour cleaning the trans lol. Thanks for everyone's help!
Custom/Ten is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:24 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com