06 King Ranch front AC trouble

[TK-Fett]

Hey guys, new member here, not much of a mechanic.

I bought my Expy last fall and didn't need to use the AC so i'm not sure how long this has been an issue. I did test it at the lot and it seemed to work very well.

Over the winter the heat worked well everywhere except the front passenger seat. The front passenger got very cold air through the dash vents and the floor with a very strong push at all times no matter what setting we had the heat on. It would stop if we turned the system off.

I was told by a local mechanic that it was probably a blend door or fresh air door issue. If I drop the glove box I can see a door move when I switch from outside air to recirculate.

Now that the temp is up I tried to use the AC. Again it works fine in the back but its developed an issue up front. Its not getting very cold, I tested the R134 and it was a little high on the pressure gage so we dropped it down just a little. Still no change in the temperature upfront. Also now we will sometimes get air out of the dash vents and sometimes we can hear the air blowing but its not coming out any vent. So far i've been able to switch between modes or turn the system off for a second and turn it back on and get the air to come out of the dash again. Also the passenger side no longer gets the very strong push of air that it did, when we were using the heat.

I do not hear any clicking inside the dash or unusual noises.

Where should I start, i'm on a budget and I can't afford the $1000 that seems to be a common quote for AC repair on these vehicles. Does anyone have any ideas on what my problem is?

Around home I can drive with the windows down but we are taking the kids on vacation and I don't want to be trapped in a hot car with them for 3 hours.

 

[stamp11127]

Post your email address and I'll send you a guide. Sounds like vac trouble.

 

[TK-Fett]

Thanks, my email is [email protected]

 

[bedrck46]

Keep the forum updated It will help others

 

[stamp11127]

TK check your email

 

[TK-Fett]

I got the email, now what do I do with it?

Like I said i'm a little mechanically dumb with stuff like this. I've never worked with an AC system and i'm worried about making it worse than it is now.

This weekend I noticed another symptom that has probably been there the whole time but I wasn't aware of. When I lose air out of my front vents but I can still hear it blowing its coming out of the defrost vents and the switch has changed to auto. Pushing the face button doesn't always change it back to the front vents and the foot button doesn't change it either. The off button still works and each time you push a button the light above it comes on to indicate that you have that option selected but the air flow doesn't always change.

I was able to get it back to the vents I wanted by turning the system off and back on or by repeatedly pressing the button (may have been a coincidence) or turning the fan to low then back to high seemed to work sometimes too.

I also tried adjusting the temperature to see if maybe that switch was the reason I wasn't getting cold air. I turned it to the highest setting and within seconds I had hot air. As I was turing it down you could feel the change with every few degrees down to 70. Anything lower than that and you couldn't feel any change in the air.

Also no matter even though I have recirculate selected the front two seats never seem to really cool down. We get cool air but that part of the cabin never really cools down so it seems like its not really recirculating the air, that could be in my head though but it seems like even with air that isn't fully cold it will still cool off some. But the rear part of the cabin does cool down and feel great.

Lastly, the outside temp in my area has been in the 90s and humid this past week.

 

[stamp11127]

I don't believe anybody is dumb - they are just uneducated in the subject. Now if you want to discuss stupid people that is for another thread...

Read what was in the email and ask questions if you don't understand the system operation. Once you do learn how the a/c system works you'll just shake your head at how much people are getting ripped off because they think it mysterious.

To answer your question though, the system is controlled by vacuum motors that open and close blend doors. Your problem is most likely due to a loss in vacuum or a motor hanging up. Usually when there is a vac leak in the interior you will hear it. Sounds just like a hiss, the worse it is, the louder it is.

Look at the diagram on page 2. The panel airflow is controlled by motor #14. A second source for a vac leak is the function selector switch and/or the lines connecting to it - see page 3 at the bottom diagram for the lines. You would looking at lines 5 & 6.

Here is a magic question - do you have the screw drivers, torx set and mighty vac in order to work on the diagnosis & testing? If not are you willing to invest in the tools?

 

[TK-Fett]

I've got lots of tools. The screwdrivers and torx bits will be no problem. I don't have the mighty vac though.

Where would be a good place to get one?

 

[stamp11127]

Check amazon, they show two sets under that name.

 

[TK-Fett]

Also it just occured to me that I recently removed the throttle body and cleaned it. If I remember correctly it had sometype of vacuum hose attached to it. Am I remembering right?

If so could that be the cause of my problem or is it a seperate vacuum system?

 

[TK-Fett]

I've printed out the first couple pages of what you sent me and after looking it over and reading it a couple times its starting to make sense to me.

I believe that I have the second type of system listed, the EATC. I have a King Ranch Expy with the push button dual climate control system. Am I correct that I have that type of system. I think the first one listed, the manual system, uses knobs instead of buttons.

 

[stamp11127]

If you don't have dials you have the EATC system. Check the vac lines in the engine compartment and make sure that they are on correctly and haven't started deteriorating. If they aren't sealing then that is a leak that lowers the amount of vacuum.
All vacuum is sourced from the engine & has many connections in the system. You only need one of them to leak to start having problems.

 

[TK-Fett]

Thanks for all the info so far. I'll start checking stuff tonight and report back.

One last easy question, at lunch I took a quick peek under the dash trying to find ATC solenoid and manifold but its not jumping out at me.

I've read that o-rings on it can often be the problem when these symptons arise and it seems easier to check than tracing all the vac lines. I'm trying to check the easiest stuff first.

 

[stamp11127]

Easiest method is to find one of the control motors and trace the lines. Or since the lines are color coded find any one of them and trace it. Don't be alarmed if you need to start pulling the console out or the dash apart to get into it.

 

[TK-Fett]

Awesome news, I found the vacuum leak under the hood last night. A hose a came unplugged in the area around the air filter. I probably pulled it loose when I was cleaning the throttle body. Plugged it back in and everything is working fine.

Thanks for all the help though. I now feel confident that if anything else funny starts happening with my vents that I can handle it myself before going to a garage.

I owe you for making my upcoming vacation a lot more exciting since I won't be sitting in a hot car on the road all day.

Now, do you have any idea what would cause the passenger side to get cold air full blast even in the winter? If you can point me in the right direction i'll see what I can do. Until a few days ago I didn't even know the system ran off vacuum lines.

 

[bedrck46]

sending you a PM

 

[stamp11127]

Look at the vac diagram for what controls the blending from driver to passenger.

I like people that own the problem they caused, there is hope for the human race after all. Have fun on your vacation.

Since your in the learning mode, which is good, take the next step on the system:

Home page: http://www.macsw.org/imis15/MACS

Home study guide for how the a/c system works: http://www.macsw.org/imis15/Images/MACS_Docs/Section609Manual12.08.pdf

Once you finish the 609 manual you'll realize what a racket these shops have going.

 

[TK-Fett]

I'll check that out about the AC systems, maybe I can get one of our old fire trucks ac to run again.

Do you think that a simple blend door would cause the passenger side to get full blast cold air even when the heat is one? Its a system with dual climate control but no matter what setting you put it on the passenger side gets super cold air all winter, even when the dual setting is turned off and the driver side is getting nice toasty air.

 

[stamp11127]

Depending on how old the fire truck system is - it may be an R12 system. Super expensive to fix, usually cheaper to change to a r134a system.

See pages 8 & 9 for the self test and page 14 in the file about dual temp not working. You need to see if there are any codes present first.

 

[TK-Fett]

Thanks, will do that tonight and report back.