heater vacum diagrams

[boechler14]

ok i have a problem wth my heater i dont know if anyone else has had this problem but it wont switch off of defrost the fan speed changes and the temp changes but always blows air fomr the defrost vent i took the glove box out this morning and when i put my hand under the dash there is a breeze i geuss now i dont know if this is normal but it may be what causing my problem is there anyway i can find the source of the air easily or am i just going to have to keep geussing..thats also why i was hopein someone would have a vacum diagram or something thanks

[slick]

Its not the vents, it's a vaccum problem. Check the small vaccum lines right near the battery, make sure there all connected. If so, then it may be your vaccum ball, it's located in your fender.

[Kalgorn]

Can you turn the fans off with the off switch?

 

If you can, I'm having the same problem you are. I can change the temp of the air, the speed of the air, and I can turn the air off but every other button just turns the air back on and keeps it on one setting. It's on blend I think (defrost windshield and blows on legs). I posted about this a while ago and someone told me it was the control unit. They said I would have to pull the control unit out and resolder some wires onto it because they came lose. If it's just a vacuum line, that would be so much easier.

[slick]

Had the same problems. Check your vaccum lines....

[boechler14]

yea that sounds liek the exact same problem as me cept mines just on straight defrost

[Kalgorn]

BTW, what car is this on?

[slick]

Shouldn't matter what car its on. It's a common problem.

[boechler14]

its on a 90 gp

[boechler14]

well i checked the hoses by the battery and under the cruise control thing and everything seems to be coneceted is it just that one rubber piece with all the lines running to it and from it ? and what fender is the vacum ball under? driver side? if so how do i get to it? do i have to remove the battery and everything?

[Bossman429]

The vacuum ball is located under the drivers side front fender. You can see it from under the car. Don't have to remove anything, just crawl on your back.

The heater controls on our cars are controlled by vacuum, if the vacuum is low, the controls default to the defroster, probably for safety reasons, since defrost is the most critical of functions during the winter months ( at least in cold places )

 

You might consider searching the forum for "vacuum" or "vacuum leak" or "vacuum gauge"

As I believe I explained how the vacuum heater controls work in more detail a little less then a week ago in another post.

Good luck

EDIT: It's not really a matter of the hoses near the battery being connected, it's a matter of wheather or not they are in good shape, and not cracking. The Battery acid eats the hoses up near the battery, they become cracked and brittle, then leak.

[boechler14]

awsome thanks well i hope i can figure this out

[boechler14]

well i spent the last 30min to an hour out in the snow lookin through all the little hoses i could find and nothin all seem damn good i even took the little piece that they all conecxt to and tested it with soapywater and no bubbles on nothin so is there any way to test this vacum ball thing? also is that little breeze behind the glove box normal?

[Bossman429]

Get a Vacuum pressure pump, I think they're about $20 or so.

Looks like a pistol grip with a gauge on it, and it is used to test for a vacuum/ leaks.

You plug a vacuum line into it and squeeze the trigger a few times and watch the gauge move up, the gauge measures vacuum pressure that you have pumped into the system. Make sure that the gauge doesn't lose pressure. If you lose pressure on anything, that is probably your leak.

Heres what should happen with each line/line:

-The main hose comes out of the intake and into a little check valve near the back of the motor, looks like a black cylinder with 2 or 3 nipples coming out of it. It is a one way vavle, so the gauge should pull pressure one way, but not pull pressure from the other end. make sure it isn't cracked.

-The vacuum ball under the fender should hold pressure, but it takes a lot of pumps to register the vacuum on the gauge.

- One of the hoses coming out of the check vavle goes into the firewall, into the passenger compartment. This line feeds vacuum to the heater controls we were talking about earlier. Pull Vacuum out of this line and make sure it doesn't go down. If it does you'll have to look under the dash, or take out the heater controls to locate the leak; I've never seen this component leak before.

-The other line out of the check vavle goes to the Cruise control diaphram, it should NOT hold any vacuum, the only time the cruise control holds vacuum is when the cruise is set (over 45 mph)

-Also check all of your lines with the gauge too; If you check the vacuum ball, move up and follow the line through the fender, and check for vacuum higher up on the system. I tested each line one by one, pump the gauge up and hold your finger tightly on the other end to check it for leaks.

Let me know if this helps, I wrote it off what I remember from the Beretta, so I might go take an actual look at it for specifics if you need more info.

Good Luck

[White93z34]

don't think my car has one of them vaccum balls, when i had my front end apart i never saw one under any fender :?

[Bossman429]

Some Luminas have it all the way in the back, near the trunk or rear fenders. I think.