Thread: HVAC Issue, Stuck on Defrost/Lower Only, Help

you found a open ended vac line, or lose where it goes?

if that other quote you had is right, try googleing for the vac ball for your year car. maybe if you can see what the part looks like you can find it in the dash somewhere. maybe rockauto might carry it.

can you pull the line off it and see if it has vacuum at the vac line?


maybe just run a new line from that box to the top of the sc? if theres no draw on the tube now.

check to see if the vac lines to the vac pumps has any suction. if not, id think that vac ball has crapped out.

thats pretty much what im thinking. pull a line off one of those vac pumps, work the air flow buttons, see if it sucks air. if not id be looking at the ac ball deal.

did you say you also swapped the climate control as well? and that didnt help either?

i was gonna pick up a junk yard unit, but im gonna start with troubleshooting like scotty said, check for vac at different points in the line.

pretty sure my vac pump is at fault. but previous owner left the vac ball unhooked and bouncing around in the bumper after he did engine rebuild, could be cracked, and i didnt notice when i put it back on.

im also gonna get some vac hose and redo the line from the ball to the firewall, just to be certain. I dont trust that plastic line.

it could be the problem. it must have been the other guy who changed his Climate Control unit with no results. there's 2 of you right now with the same problem. you both lack a fender vac ball too.

id go pop a line off the vac actuators under the dash, see if they have vacuum, if not your problem is under the dash.

you should be able to move the arm off the vac actuators by hand, and that should move the flow of air. at least that way you know the linkage is still good, and not broken.

I'm having the same issue. I checked and I,m not getting vac to the actuator. Can I just bypass the vac ball and T into the S/C vac.

some cars have a vacuum ball in the drivers side fender, and some have it under the dash. that part or the climate control its self may be bad.

I have the vac ball. The line was broke by the battery I fixed it and still nothing. So to check the actuator I Tee'ed into the S/C vac and it worked fine. I thinking I can just reroute the vac line and it will be good.

so you took the vac line off the top of the sc, then T'ed it else where and the controls worked?

did you have to cap the tree on the sc top where the line was? was there vacuum at the tree with the line off? if not maybe the tree is clogged up.

My car only has 2 spots on the vac tree. One goes to the fuel rail the other to the boost controller?. I wouldn't surprise me if the last owner changed something.

you got a 97 with a vac tree on the side of the sc, the vac line for the hvac comes off the top tree, that also leads to the break booster. should be 2 small and one large tube on the top tree.

Yeah and the middle small port has a cap on it. Well now I know why I'm not getting vac. Where should the line run to?

the line by the battery that broke on you, it tags the fire wall via a loop and screw to hold it there, then it would go to the capped port on the top tree.

you can see it clipped by the alt on the fire wall, then it leads to the sc top tree.