Odd air conditioning issue

[Dkodgis]

My 2003 Eddie Bauer had an air conditioning issue. At times, the air conditioning was blowing out of the main front vents then the air would stop blowing at all but the fan was still running and it sounded like air was blowing...just no air coming out of the main vents while the air was on...for about a minute and a half. Air was cool and not cold. Inspection under the hood found Freon leaking from the compressor. It could have been the o rings or the compressor but with 13 years on it, I changed the compressor and the accumulator (where I add Freon) and charged it to 48 lbs. The result: much colder air, no leaks but still that intermittent stopping of air blowing out the main front vents. It is much better than before and only happens infrequently now and the air blowing comes back in a much shorter time. Infrequently=two or three times a day. Air conditioning otherwise is fine.

So does anyone have an idea why the air could stop blowing completely for 30 seconds to a minute and then come back full force? Could it be the cycle switch or delivery of air issue as with a leaking vacuum hose messing with the opening and closing of the vent doors inside the console? Heat works fine with no issues with air coming out of front vents. When it is comfortable outside, say 70, and the air is not on and just vent air blowing, the air always blows out strong and never stops. I have searched the internet and I can't figure it. It seems either the air is blowing or not blowing and there is no intermittency. Any suggestions would be appreciated.

 

[Joe in NY]

does the air come out of any other vents? There is Foot, Panel, Defrost, and the rear center consul vents

 

[Dkodgis]

yes. it comes out of the vents i select but i always leave it on main front vents. if it stops blowing ican feel it coming out of the defroster ventsuntil it switches back to bloeing thriugh front vents by itself

 

[Bulletslinger]

try leaving your air re-circulation off and see if it still does it then

I had the same problem with the air coming out of the defrost during load/acceleration

did the smoke test with no apparent vacuum leaks.

and by some random stroke of luck, I decided to leave the re-circ off to see what that would do, and BOOM, problem was gone.

There was a bad vacuum motor, part number 18A318.

https://www.rockauto.com/en/moreinfo.php?pk=380478&jsn=511

 

[lincolnshibuya]

you have the manual ac? normally it's a vacuum issue and happens when engine is at full power (low vacuum) it's possible that a vacuum hose is broken or a leak in the vacuum reservoir.

I got that same issue with my Jeep and they even have a TSB for that kind of issue.

 

[Bulletslinger]

I'm guessing he has auto/digital ac controls instead of manual controls

 

[Bulletslinger]

and I don't know if that's the exact part, so take your chances, but that's what it looks like. They used that part multiple times throughout the HVAC vacuum system

 

[Dkodgis]

everyone thanks for the ideas. i have non-manual controls as in digital. I guess it is an air delivery thing and it most likely involves that solenoid be ause it seems logical a drop in vacuum causes the shift from front to defroster to front vents. if it were a hose then the leak would be fairly constant, right? again thanks for the ideas!

 

[Dkodgis]

Could someone point me to where the control valve assembly is located? Do I have to take the glove compartment out for example to find it? I would appreciate it if someone could tell me/give an idea. Bulletslinger called it a vacuum pump. Thanks in advance.

 

[Bulletslinger]

Vacuum Motor actually

not sure if that's the same thing

all I know is, when I had the problem fixed, the part I posted is what they showed me

 

[Number Twelve]

Do I have to take the glove compartment out for example to find it?

It depends on how big you are. Most of the vacuum gizmos are under the dash on the passenger side. I'm really old, so I took out the passenger seat and the glove box (which isn't difficult). If you're 8 years old you can fit under there nicely, but if you're a full grown person, it makes all the difference to get the obstacles out of the way.

4 bolts and a couple of electrical connectors to get the seat out, start with the hinge screws on the glove box, then squeeze it to get it to pop out.