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

Air Ony Discharges From Defroster Vents: All Lines Connected And Intact

  • Thread starter Thread starter garystocker
  • Start date Start date Jul 25, 2012

garystocker

Member
Jan 2, 2005
305
0
17
60
New Jersey
Jul 25, 2012
#1
  • Jul 25, 2012
  • #1
No hiss when selector is positioned between floor, def, vent, mix, etc.

I get a few pumps of the power brake via vacuum stored in canister when engine is off.

I followed the lines under the hood that run from pass firewall to passenger side vacuum tree, to across the firewall to the power brake booster vacuum tree.

Looks good under the dash. Connected and intact.

Now What?
 

blackstangt

Member
May 31, 2004
460
1
19
ny
Jul 26, 2012
#2
  • Jul 26, 2012
  • #2
If you have some vacuum tube lying around, try swapping it, you may have a crack somewhere hard to see. Try to open the vents manually (under the glove compartment), see if they stay. I wonder if testing using a vacuum cleaner would work or potentially do damage...
 

tca7291

I can see your wieners.
5 Year Member
Sep 1, 2011
1,801
152
143
Raleigh, NC
Jul 26, 2012
#3
  • Jul 26, 2012
  • #3
I was looking through my service manual earlier about this, and was thinking your defrost vacuum motor was stuck, but if that was the case you should still be able to get air on the floor vents as well depending on what you have it set to. I would assume a vacuum leak some where in the control, or maybe a clogged port on the control valve.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Jul 26, 2012
#4
  • Jul 26, 2012
  • #4
A vac cleaner will not test lines. It has volume but not strength enough. A hand vacuum tester pump is made for that.
 

jrichker

StangNet's favorite TOOL
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Dublin GA
lowendmac.com
Jul 27, 2012
#5
  • Jul 27, 2012
  • #5
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/ Everyone should bookmark this site.

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

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

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

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