AC suckage

[Austin]

Here's the scoop. We'll start at the dash switch. Keep in mind it isn't the auto fancy digital deal.

Defrost - works. Others - don't.

Temps - hot and cold will blow out of defrost.


I've narrowed it down to either blend door or vacuum... If I do the blend door mod, though, do I lose the defrost?

Dennis - have a vacuum diagram for me? (v6)

 

[blacksnapon]

My vote, vacuum. Its engineered that if you lose vacuum, it defaults to defrost only (so at least your windshield will be clear).

 

[Austin]

Okay. Any areas I should begin my search?

 

[RangerPilot]

check the lines where they go through the firewall. You can also pop the radio and see the lines coming straight out of the A/C unit if I remember correctly.

 

[Austin]

I'm in the dash now... But I can't seem to find if it's the controller or somewhere down the line. I've checked behind the switch and at the splitting point just past it.

 

[Austin]

FIXED IT! There was a line not connected to a reservoir. Credit to explorerforum.com

This would be the culprit: (not my pic)

 

[Fellro]

That would do it. Reason to not suspect blend door in these situations: you had temp variations. What a blend door does: control the temperature. The door that matter controls whether the air comes out the vent, the defrost, or the floor vent. As Vince stated, the no vacuum situation is indicated when it is defrost only. However, on my non-factory air 88, it has a cable ( which has a broken control lever) that controls heat or defrost.

 

[Mil1ion]

Ford has 90's AC blend door issues in several Vehicle lines.

One has to know the exact application because they changed how they were controlled.

Earlier years they used a vacuum motor

In 1992 (in certain vehicles) they used a 12v DC motor that was both normal and reverse polarity actuated.

On the 88 Lincoln the temp monitoring module once faulty defaults to defrost only.

I am battling heat in passenger compartment issues on 3 vehicles right now..all Fords.