Heater troubles - 89 mustang

[mrmustangman357]

I just swapped out the heater core in my 89. I unbolted the dash, console, steering column, etc. but none of the wiring. Now testi9ng the heat with the dash still off, the heater controls don't work. No blower motor, A/C, or nothing. I did a quick scan of the area and i saw no wiring disconnected. Anywhere I should look first? Is there something of the dash not being on that is causing the blower motor not to run?

 

[savegoodautonfg]

Check for a yellow vacuum line right above the pedals in drivers side.

 

[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 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

 

[mrmustangman357]

I guess with the dash disconnected, a ground wire was not completed. with the dash hooked up. it works fine. yay heat!

 

[mrmustangman357]

new problem. just discovered it. regardless of what selection I make on the control panel (floor, mix, etc), it always comes out the defrost. Any ideas?

 

[mrmustangman357]

should I be looking at a vacuum line, or something else? thanks for the above diagram too

 

[93green_gt]

I have same problem on my 93gt

 

[mrmustangman357]

I think that diagram is wrong. the yellow vac line that does to the defrost window has no channel in the defrost section? I think that may be wrong, among other things.

 

[mrmustangman357]

the black line going into the firewall that feeds the whole assembly was clipped. replaced the line and problem solved

 

[SuperStang83]

It could be the line under the steering column. It might have come undone and you need to get up there and plug it back in. There may be a bracket in the way that you can remove to get some room up there. The bracket only has two torx screws.