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 12-04-2017, 08:07 PM   #1
84C10EC
Registered User
 
Join Date: Nov 2017
Location: Decatur, IL
Posts: 25
AC Vacuum Harness - Please Help

Looking for a new AC/Heat Vacuum Harness. Mine has dry rotted and needs to be replaced. I've looked on several truck part sites and ebay but cant seem to find one. Any help in the right direction would be appreciated.
Attached Images
 
84C10EC is offline   Reply With Quote
Old 12-05-2017, 11:10 AM   #2
RotaryRocketeer
Registered User
 
RotaryRocketeer's Avatar
 
Join Date: Jul 2017
Location: OKC, OK
Posts: 247
Re: AC Vacuum Harness - Please Help

You looking for the adapter, or the lines? The adapter can be purchased through LMC. I imagine you'd need to get the right size line by the foot and cut to fit.
RotaryRocketeer is offline   Reply With Quote
Old 12-05-2017, 01:48 PM   #3
84C10EC
Registered User
 
Join Date: Nov 2017
Location: Decatur, IL
Posts: 25
Re: AC Vacuum Harness - Please Help

Thanks for the reply. The harness itself is fine. Its the line that goes through the firewall and to the engine (gray stripe) that is dry rotted. I will attempt to see if I can get the line out of the harness and repair it. One more question if I can. Because the line is dry rotted I do not know where on the engine it attaches. If anyone could share that knowledge it would be much appreciated. It appears to go somewhere near the distributor.
84C10EC is offline   Reply With Quote
Old 12-05-2017, 01:56 PM   #4
wilkin250r
Registered User
 
wilkin250r's Avatar
 
Join Date: Sep 2010
Location: Lake Tahoe, Nevada
Posts: 755
Re: AC Vacuum Harness - Please Help

I think it goes to a vacuum canister just above the fan, and that canister has a line running to the intake manifold or carburetor (really, any vacuum source will work, but I don't suggest the ported vacuum)
__________________
I know a little about cars, but if you have a question about electricity or sport quads, I'm your man!!!
wilkin250r is offline   Reply With Quote
Old 12-05-2017, 02:00 PM   #5
RotaryRocketeer
Registered User
 
RotaryRocketeer's Avatar
 
Join Date: Jul 2017
Location: OKC, OK
Posts: 247
Re: AC Vacuum Harness - Please Help

Maybe, and I'm just guessing here, it's the one that should connect to the vacuum canister/ball in the corner on the passenger side of the firewall?
RotaryRocketeer is offline   Reply With Quote
Old 12-05-2017, 02:25 PM   #6
SunSoaked
Registered User
 
SunSoaked's Avatar
 
Join Date: Dec 2011
Location: Yuma Arizona
Posts: 1,525
Re: AC Vacuum Harness - Please Help

I just swapped manifolds and was cleaning up the firewall on my 85. I was wondering myself last night where that vacuum line went to inside the cab. On the firewall side it goes to the vacuum ball. My ball is below and next to my master cylinder.
SunSoaked is offline   Reply With Quote
Old 12-05-2017, 03:07 PM   #7
RotaryRocketeer
Registered User
 
RotaryRocketeer's Avatar
 
Join Date: Jul 2017
Location: OKC, OK
Posts: 247
Re: AC Vacuum Harness - Please Help

Sounds like we're on the same track. Must be in a different spot on the later models. My knowledge is limited to my own '76.
RotaryRocketeer is offline   Reply With Quote
Old 12-06-2017, 10:01 AM   #8
wilkin250r
Registered User
 
wilkin250r's Avatar
 
Join Date: Sep 2010
Location: Lake Tahoe, Nevada
Posts: 755
Re: AC Vacuum Harness - Please Help

Looking through pictures of engine bays, the vacuum balls all look similar, but they're mounted in different places. Many are attached to the heater/AC housing, I believe mine is attached to the firewall itself on the passenger side, and it sounds like SunSoaked has his more driver's side.
__________________
I know a little about cars, but if you have a question about electricity or sport quads, I'm your man!!!
wilkin250r is offline   Reply With Quote
Old 12-06-2017, 05:32 PM   #9
84C10EC
Registered User
 
Join Date: Nov 2017
Location: Decatur, IL
Posts: 25
Re: AC Vacuum Harness - Please Help

I only have one and its on the firewall on the drivers side. Looks like the cruise control is the only thing accessing it. I'm going to "t" into the line above the check valve. I suspect that will work. Thanks all for the reply's.
84C10EC is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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 03:46 AM.


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