I started working on my AC problems today. Typically I have been getting 57-59 degrees out of the vents. I put one can of freon in and the temps dropped to the about 50 degrees. Obviously I was low on freon. I should get some gages to help me get the right amount of freon in.

I then put some foam insulation around the exposed metal lines that condensation forms on. I figured that minimizing cooling loss would improve system efficiency.

I then went for a drive. It was nightime with the temp about 80 degrees. The lowest the AC vent temp got to was 47 degrees. It sure would be nice to do better than that.

In an earlier post I had proposed putting a heater-core cut-off valve in. I would think it would help as my AC-off vent temps are up to 10 degrees higher than ambient temperature. I see there is some concern regarding potential engine cooling problems. It would be nice if Ford would let us know if cutting off the heater coolant flow would be OK.

Pete

99 CC V-10

 

I picked up my truck tonight and was told that because my temps are within Fords range of normal, Ford will not pay the dealer for any more warranty work on my a/c system. The service guy said that they understood my problem and knew they could fix it, but Ford will not authorize it. Basically it seems that it is the heater core and / or blend door that causes some trucks to have under performing a/c. Putting ball valves in the coolant line is not a Ford approved fix, so the dealer can't do it. They did say however, that they did not see a problem with the mechanics of that fix, just that they would not do it. They said that the blend door was a real big job to get access to and they could not investigate that further unless the a/c system problems were severe enough to fall ouside of what Ford says are normal temps.

I did get them to drain and recharge the system again as they did 6 months ago when it was a little short. This time they said it was 3 tenths of a pound of refigerant short. On the way home I got a couple of degrees cooler than I had been getting so that helped a little. Thing is if the system lost 3 tenths in 6 months, I think that constitutes a leak. Am I wrong? They seemed to be implying that 3 tenths was not enough to notice. I will watch the temps and if they go back up over the summer and fall, I will bring it to them to check that again. They told me that there was a dye in it now to make any leaks obvious. Does that sound right? Is there really a dye they add to the refrigerant to see leaks?

 

Pete, I have not heard specifically that the valve would make a noticable difference in engine temps but a few people here have concerns about that. My dealer implied, without actually coming right out and saying it, that the valve fix was well known and not a big issue. They won't do it however. Ford will not approve it as this would admit there is a problem that needs to be fixed. I have seen a few post on other a/c topics on this board by people in the business with a lot of experience and knowledge. It would sure be nice if one of them comes upon this thread and could address this heater core cutoff fix directly.

>
>In an earlier post I had proposed putting a heater-core
>cut-off valve in. I would think it would help as my AC-off
>vent temps are up to 10 degrees higher than ambient
>temperature. I see there is some concern regarding potential
>engine cooling problems. It would be nice if Ford would let
>us know if cutting off the heater coolant flow would be OK.
>
>Pete
>
>99 CC V-10

 

Here is what guy did.
"For those interested in stopping the air temp increase across the heater core, I have the following info. Go down to your local NAPA store and purchase part # BK. 660-1413, heater valve.. This is a small pitcock type valve that is made just for this application. It makes for a neet installation. I installed mine on the heater line that is the discharge from the waterpump; up about a foot from the pump , between the two bends in the hose.. Easy to get to. You'll need two hose clamps also...My AC discharge temp went down about ten degrees after install. At an ambient temp of 92 degree F. the discharge was 40 degree after install.. Hope this helps..."

 

benr0 - Thanks!

For those of us, (like me) that are not well educated in these things, please explain exactly how this works. What happens in the winter when you want the heat?

 

This is just a shut off application, you would have no heat until you opened it up.
I don't know if anyone has done this, open it up a little and keep a small amount of coolant flowing all the time. You would not get full benefit for cooling improvment, but you would get a small amount of heat.

 

[updated:LAST EDITED ON 09-Jul-02 AT 05:28 PM (EST)]Thanks again ben0, I get you now. This has been talked about earlier in the thread. Some think that it would be better to use t's to put a hose across to the hose on the other side of the heater core to keep the coolant flowing, just not through the core.

I have not done either yet. A couple of weeks ago I had them look at the system again, even though it is within Ford's range of normal. The dealer did not see on the computer that they had drained the a/c system and recharged it 6 months ago, (and found it low) so they mistakenly did it again to see if it would help. Like last fall, it did help a few degrees, so I can live with it for now. I suspect the temps will go back up in time. They put in a dye but could not see any leaks. The system had lost .3 (3tenths)of a pound of refrig. in 6 months. They weakly tried to tell me this was normal, but I was not going for it. They said they would look for leaks when I am in for my next oil change or if I notice an increase in temps before then.

Does anyone here know if any loss of refrig is normal after 6 mos, or should the system be completely sealed?

 

I don't know a lot about A/C but I would think any loss of refrigerant means there is a leak. I thought that that A/C systems were closed systems. For instance, I have a window unit in my shops break room, had it for 5 years now, never needed it serviced.
When I was younger and living at home, I don't remember dad doing anything but sticking them in the window.
The A/C system at my house was installed 11 years ago and hasn't been touched.

3/10's of a pound loss in a system that only holds less than 3 pounds, I would consider a LEAK!

Just rambling, I will see if I can get a hold of my friend at the dealer, he'll tell me whats up, plus he owes me $$$$.

 

IM still cooling about 47, on a 90 Florida day.
only takes about 10 min. to freeze you out.
Gota love it. Remember, we are talking about something
"man made"

 

There are multiple fixes for this A/C system. From reading this whole post, most of you are experiencing correct air temps from this air handling package. Some of the info that was written was correct, some was not. If anyone is interested I can post what I have done to my 01' SD, on the recommendation of a former Ford/Visteon climate control engineer. I am extremely happy with the air that I have, and I only made one change. I rarely use high blower with ambient temps below 90F. It's just too cold.
xc600----aka-Alan
Visteon Climate Control Lab
Windtunnel operations

 

>There are multiple fixes for this A/C system. From reading
>this whole post, most of you are experiencing correct air
>temps from this air handling package. Some of the info that
>was written was correct, some was not. If anyone is
>interested I can post what I have done to my 01' SD, on the
>recommendation of a former Ford/Visteon climate control
>engineer. I am extremely happy with the air that I have, and
>I only made one change. I rarely use high blower with
>ambient temps below 90F. It's just too cold.
>xc600----aka-Alan
>Visteon Climate Control Lab
>Windtunnel operations


We are always interested !,post away Alan!

Rich

 

[updated:LAST EDITED ON 10-Jul-02 AT 02:30 PM (EST)]Please Alan, post all you know, with as much detail as you have time for. Thanks!

Yes, it seems that much of what is posted here is within "normal" for this system. The thing is that just a few degrees can make a big difference in comfort level. The two times the dealer recharged my system, the temps blowing out the vent only dropped by 3 or 4 degrees, but this made a difference in the comfort of the crew cab. I noticed it right away and was surprised when I measured the temps that it was only this small a drop in temp. It felt like more. So anything you can contribute to make even a small difference will really be appreciated!

 

[updated:LAST EDITED ON 10-Jul-02 AT 02:40 PM (EST)]I am happy with the AC in My 99, and I live in Fl.
But I would like to here the fix also. Never to old
or stubborn / hard headed to learn.:-)

 

I will check the temp I have coming out of my LC register on the ride home tonight and compare that with outside ambient. When I get numbers to post I'll include what I have done and what I have been told will additionally help. Please keep in mind though outside temp, humidity, how long the engine has been running, engine size, all come into play. Designing these systems to work in all conditions well isn't always easy.
Alan

 

On a recent long trip I monitored the A/C temperature with a thermocouple probe on my 2001 S/C. The outside temperature was 98° and my output temp fluctuated between 48° to 52°; it was roughly the same on all blower speeds and norm or max. (it was a LONG trip up I5, so I had plenty of time to experiment!) I also notice, as some others have, that the air output in "vent" is a bit warmer than outside air- even on days that are not all that warm, it seems necessary to run the a/c. So, I think that we are on the right track w/ the blend door/ hot water valve. My old '71 LTD has a valve that blocks the coolant from the heater when the cool/warm "slider" is all the way to "cool"
According to the light truck shop manual, the Excursion w/ aux heat/ac has a vacuum operated valve inline with the heater core. The valve will block coolant to the heater core when the control is set to "max". I checked the parts catalog and sure enough, one is listed. I have ordered one from carparts.com so I could see what it looks like; I'll let you know what it looks like when it comes.