• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

What color vac line is from intake to cluster under glovebox?

  • Thread starter Thread starter GT_Rich
  • Start date Start date Feb 6, 2008

GT_Rich

Member
Dec 11, 2005
172
0
17
North Canton, OH
Feb 6, 2008
#1
  • Feb 6, 2008
  • #1
There is a junction point under the glovebox of my '92 which has red, white, blue, and black colored vacuum lines. What line is coming from the intake?

During my hide everything and delete heat and a/c last winter, I cut the line going through the firewall, and now I have no vacuum going to my hvac controls. I'd like to at least use the vent again Thanks in advance.
 
S

silver87

New Member
Jul 4, 2004
115
0
0
Northern California
Feb 6, 2008
#2
  • Feb 6, 2008
  • #2
if im not mistaken, it is the black one
 

4G-KDMP

10 Year Member
Jul 23, 2005
935
19
39
CA
Feb 6, 2008
#3
  • Feb 6, 2008
  • #3
Black for sure!
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Feb 7, 2008
#4
  • Feb 7, 2008
  • #4
Diagram courtesy of Tmoss & Stang&2birds


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer, actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
 

Attachments

  • Mustang_AC_heat_vacuum_controls.gif
    17.8 KB · Views: 506

GT_Rich

Member
Dec 11, 2005
172
0
17
North Canton, OH
Feb 7, 2008
#5
  • Feb 7, 2008
  • #5
Thanks everyone, and especially jrichker for that diagram. I even went to his site looking for a diagram like that, and couldn't find it!

Do you think the check valve and reservoir are needed? I was planning on taking a line right off the manifold and going to the black line at the cluster under the glovebox. I could always add the reservoir and valve back in if I had to, but I'd rather not have to find the room for it.

Also, I don't understand the purpose of the cluster I keep talking about. From the diagram, it looks like everything comes from the HVAC controls and goes directly to a component. Why would Ford splice all of them at one point?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Feb 7, 2008
#6
  • Feb 7, 2008
  • #6
GT_Rich said:
Thanks everyone, and especially jrichker for that diagram. I even went to his site looking for a diagram like that, and couldn't find it!

Do you think the check valve and reservoir are needed? I was planning on taking a line right off the manifold and going to the black line at the cluster under the glovebox. I could always add the reservoir and valve back in if I had to, but I'd rather not have to find the room for it.

Also, I don't understand the purpose of the cluster I keep talking about. From the diagram, it looks like everything comes from the HVAC controls and goes directly to a component. Why would Ford splice all of them at one point?
Click to expand...

The vacuum reservoir insures that under low vacuum (full throttle) or no vacuum (engine off) that the HVAC controls still operate. Image losing your defrost during a cold night when you want to enjoy the pleasing effects the cold air has on engine performance. Floor the throttle and the defroster quits and the windshield fogs over.

The check valve helps make sure that the vacuum in the reservoir is always higher than the intake manifold. It helps insure that there is plenty of vacuum in the reservoir to operate the HVCAC controls. Without the check valve, anytime the vacuum in the intake manifold dropped below the level of the reservoir, the reservoir would empty out. No vacuum in the reservoir and the HVAC controls quit working until the vacuum builds back up.

The splice that brings all the vacuum lines to one place is probably there to make it easy to disconnect for removal or test the HVAC controls.
 
You must log in or register to reply here.

Similar threads

Mustang II 4 cyl gear hunting and possibly messed up vacuum system
  • oesterreicher
  • May 31, 2026
  • 1974 - 1978 Mustang II Talk & Tech
Replies
11
Views
319
1974 - 1978 Mustang II Talk & Tech Jun 14, 2026
manicmechanic007
Resolved No air to the vents, only air to the defrost and feet
  • Dontknowchit
  • Mar 9, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Sep 30, 2025
Dontknowchit
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
M
Progress Thread mnky99 2001 V6 evap core, ac compressor, heater core replacement
  • mnky99
  • Sep 5, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
529
1996 - 2004 SN95 Mustang -General/Talk- Sep 5, 2025
mnky99
M
A
Vacuum line help
  • Artyom
  • Aug 27, 2024
  • 1994 - 1995 Specific Tech
  • 2 3
Replies
40
Views
4K
1994 - 1995 Specific Tech Sep 26, 2024
Artyom
A
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?