89 ac/heat all comes out the defrost duct

[sacky07]

My 89 doesnt have heat but the ac works. No matter where the i turn the knob to it all blows out the defroster duct onto the winshield. Is this a vaccumm line problem behind the heater/ac controls? Thanks Dustin



edit: sorry, i should have searched first, please delet.

 

[Green 94 5.0]

It is going to be a hard vacuum line that runs across the firewall. Trace those likes back and you should find a break in it somewhere.

 

[sacky07]

Would bad vaccum lines cause the temperature control knob to be really stiff too?

 

[4G-KDMP]

The vacuum has nothing to do with your temperature control knob.

The temperature control knob has a black shielded cable with wire inside that is either pushed or pulled when you turn temperature control knob.

 

[jrichker]

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 Mustang FAQ - Wiring & Engine Info 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

 

[sacky07]

yellow line and black line were un hooked, thanks fellas