Hey guys, I'm having some AC/heat issues. Air is only coming out of the defroster. I've read that this is the default position when there is no vacuum to direct the air. I checked the vacuum lines in the engine bay and they all look to be in really good shape. My question is, what should be my next step. I live in phoenix and we're gonna be in the teens all next week so I need to figure this out soon. Do I need the take the dash apart? Is it a simple fix that I overlooked? Please help me out so I don't die of a heat stroke haha.

 

Did you check the vacuum line that goes all the way under the front bumper and back to the fire wall ?

 

Looks can be deceiving. The vacuum line originates at the intake then follow it back and if necessary physically check it for vacuum. It terminates at the vacuum reservoir which is behind the front right bumper. There are "t"s where the heater hoses go through the firewall (that one gets brittle) and at the cruise control on the front right inner fender (inside the hood) if yours has cruise. Also give a year and maybe we can get more specific.

 

that's really helpful, thank you. it's a 1990 so the renix years. i found a broken off nipple that i can't find the part number for. i'll send in some pics tomorrow and i'll double check for those hoses you told me to look at. thanks again.

 

 

do you have cruise control? that works on the same vacuum supply line...does it work

 

On my 1990, same symptom. cause was that the vacuum line got kicked off the servo motor for the air control flaps. this line and servo motor are in the passenger front foot well. my xj is missing the cover that protects this servo motor, so the it got kicked and the line fell off. check the foot well.

be cool.

 

this is the part that is broken that I can't find a picture of. I do have cruise control and it's not working either. Is this part the solution to the problem or is it unrelated. I traced the vacuum lines through this part too.

 

Any leak in the system will give you both issues. Fix every one you see. The reservoir ball can also be cracked.

 

Ok thanks, do you know what part that is that I attached?

 

Most of this system can be repaired with standard vacuum line and plastic piping.

 

sorry if it wasn't clear in the pictures, but, the big black piece has a nipple that has broken off. you can see that one of the tube ends is dangling off to the side. do you know which part that big black piece is?

 

Trace the output shaft of that actuator see where it goes. If its the throttle then its cruise control...it might go into the dash to control the blend doors.. i dont know renix configs but either way thats your problem. The broken off nipple in the black hose is a hole letting all your vacuum escape. You need to pry it out and get a plug at the auto parts store or do a really good job of sealing the end with electrical tape.. that actuator will no longer work .you probably can't repair the broken nipple

 

Yes, that's the cruise control servo. It's vacuum actuated. That's the vacuum supply that broke off. Look below the servo to see if the line is still there, then plug it. You CC won't work, but perhaps your AC will.

 

How would I plug the hole without making it permanent? The guy above said I could get a plug at an auto parts store, would that be permanent? I know it's probably a shot in the dark but I would like to eventually try and fix the nipple to get my cc to work (it's pretty nice on road trips). I tried epoxying the nipple back on and lost in the engine bay which really sucked haha.