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 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 09-08-2004, 11:16 AM   #1
TwinTurbo
Registered User
 
TwinTurbo's Avatar
 
Join Date: Sep 2003
Location: The Netherlands
Posts: 994
What's the light blue/ green wiring for??

What's this wiring for? The wiring comes through the firewall through a small hole just left from the fusebox. Is this from the cruis control system???


Marck
TwinTurbo is offline   Reply With Quote
Old 09-08-2004, 12:40 PM   #2
smokinn
Senior Member
 
smokinn's Avatar
 
Join Date: Aug 2002
Location: omaha,Ne
Posts: 617
What year and motor size might help.
smokinn is offline   Reply With Quote
Old 09-08-2004, 12:41 PM   #3
TwinTurbo
Registered User
 
TwinTurbo's Avatar
 
Join Date: Sep 2003
Location: The Netherlands
Posts: 994
83 used to be 305 / TH350
TwinTurbo is offline   Reply With Quote
Old 09-08-2004, 01:21 PM   #4
swervin ervin
You get what you pay for
 
swervin ervin's Avatar
 
Join Date: Dec 1999
Location: Cherryville, NC
Posts: 4,798
On my 85, there is a grommet beside the fuse box, engine side. It's not a flat grommet but bulges out. Anyway there is a light blue wire and a green wire coming out. The light blue wire goes to the low vac switch for tranny lockup. The green wire goes to the coolant temp sender. Is your TH350 a TH350C with lockup?

Hope this helps.
__________________
Mike

1985 Chevy C-10
swervin ervin is offline   Reply With Quote
Old 09-08-2004, 04:34 PM   #5
TwinTurbo
Registered User
 
TwinTurbo's Avatar
 
Join Date: Sep 2003
Location: The Netherlands
Posts: 994
Mine has a 400 now. The blue and green wire share a connector
TwinTurbo is offline   Reply With Quote
Old 09-08-2004, 07:41 PM   #6
swervin ervin
You get what you pay for
 
swervin ervin's Avatar
 
Join Date: Dec 1999
Location: Cherryville, NC
Posts: 4,798
I have changed so much wiring on mine, it may not be the same. I can't remember if I've changed any wiring coming out the grommet or not. It's very possible that both wires at one time went to the low vac switch. The stock wiring for the lockup was a total mess with wires going every which way. My wires may just be where I reran my lockup which consists of one wire now, and the other (green) wire may be where I ran a new temp sender wire. I'm just not sure.

Do you have a low vac switch still mounted on the firewall, or did you ever have one? If you do, see if the plug fits the switch. It's a tiny plug and will only fit it and nothing else.
swervin ervin is offline   Reply With Quote
Old 09-08-2004, 07:51 PM   #7
MidnightBlues
Registered User
 
Join Date: Oct 2002
Location: The Netherlands
Posts: 118
Hi Marc,

The green wire is a test wire for the (low vac switch) lockup system.
The blue wire is supposed to go to the brake cancel switch.
But you don't need all this with a 400 tranny.

greetz :p
__________________
*Andre*
1984 C10 SWB, 350/700R4
MidnightBlues is offline   Reply With Quote
Old 09-08-2004, 08:04 PM   #8
TwinTurbo
Registered User
 
TwinTurbo's Avatar
 
Join Date: Sep 2003
Location: The Netherlands
Posts: 994
ahh.thanks, torque converter lockup control ... don't need that indeed
TwinTurbo 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 04:39 PM.


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