A/C problem

[kbsonicstang]

ok guys i have another problem and need this thing fixed quick, cause there calling for high 90's into the triple digits this week. my a/c, it will come out the floor and defrost, but not the center vents. and i can switch where i want it to come out of, but it wont come out the center vents. and i know the HVAC controls are vacuum controled, i just dont know what vacuum line i need to replace, or fix. and i know that i have a broken vacuum line on the pass. side firewall. is this the one that needs fixed, because there are three other vacuum lines not hooked up(prolly for the cats?) if that is the one that needs fixed where does it hook up to other than the firewall? thanks for any help you can provide.

Joel

 

[FISHTAIL]

Well, you definitely need to fix any vacuum leaks you know you have. Once you fix any you are aware of, then see if it works. If it's still not working, remove your glove box. That will let you see the side of the airbox where I think the vent control solenoid is located. There are a couple on that thing, and I forget which one is for the center vents.

Anyway, fix the leaks you know about. Check vacuum at each of the solenoids on the air box, and replace the line that doesn't have vacuum, or if they all do, then replace the only solenoid that won't be working.

 

[4valvemach]

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

This may help you

 

[kbsonicstang]

does anyone know where the vacuum tank is located at? becaue one of the two hoses(closest to the passenger side) coming off the check valve is the one that is just plugged with a screw. and i belive this is the one that is connected to the vacuum tank, because the other hose goes into the firewall.

 

[4valvemach]

http://www.allfordmustangs.com/forums/attachments/5-01-tech/22958d1169448071-1991-mustang-g

Inside the passenger fender I think it looks like a softball just black towards the rear of the RF fender.

 

[kbsonicstang]

on the back of the HVAC controls there is a vacuum plug, and on the there, there is a black/yellow vacuum hose. does anyone know where this plugs in at??

 

[kbsonicstang]

ok guys. i found the selinoid that the black/yellow vacuum hose hooks up to. and i also fixed(put a whole new one on) the broken hose(one connected to the vacuum tank). after doing this, it fixed my problem completely. but i went outside to see if it still works, and wouldnt you know it, it dont work. air only blows out of the defrost and floor, no matter what you put it on. so does this mean the vacuum tank is broke?? or is it my vacuum hoses that are hooked up to the switch broke??

 

[javierrflores]

I had a similar problem with my 5.0, on idle all vents worked, it was under acceleration where my ac would blow through the defrost. I also checked all vacuum lines an was stuck trying to figure it out. Took the pass side fender-well off in order to get to the vacuum reservoir and that was the culprit, the vacuum line was broken somehow about an inch from the reservoir. fixed