Sounds to me like your TXV valve is 'stuck' in position. Just because you have a cold evap core does not mean TXV valve is working. I suspect it can only work wihen you don't have air flowing over evap core. It sounds as if TXV is not opening properly to expand gases appropriately for the load.

If I were you, I would punt and take it to the Ford dealer or any good indy A/C shop that is familiar with dual A/C evap systems (most large SUVs have same).

I'm very curious what you find out...

 

@ Superdave, no problem and thanks for the idea's!

@ Forest, I guess that is my last option. Are you suggestion I take it in and have it looked at, or just have them replace the TXV? How much do you think a shop would charge to replace it if I already had the part? I'm wondering if it would be worth just having the evac the system and then do it myself.

 

Sometimes, and I hate to admit it, I have spent too much money because I thought I could save it by doing the job myself. One example was when I replaced my alternator about 4 times before finally going to the dealer.

I'm just thinking these guys may know exactly the problem from long experience rather than experimenting with parts. You don't have the time to experiment and I know how important A/C is this time of year.

If you have a good relationship at a local Ford shop, see if they can estimate the charges for you in advance.

 

Ok. Last year another guy took it in to the dealer and they said it could be anywhere from $500 to $2K because they would have to tear the whole interior out to find it. They also said chances were it was a blend door. Obviously they didn't know what they were talking about as that doesn't make sence. I will look around for a good indy shop.

It scares me to have dealers work on my cars. You know what I mean?

 

I had the same problem, replaced the TXV for about $30 and another $100 to get the a/c evacuated and recharged.

 

It fixed your problem?

 

I have a 2003 V-10. When I first got it I thought I would need to charge
the air cond because it would not get cold. Just for the heck of it I turned the back air on and what do you know it makes the front one blow cold.
Is this normal operation for these trucks? Seems silly that you have to turn the back on to make the front work.

 

Update on my 2005:

After taking the entire rear quarter panel trim out, I learned two (2) things:

1) My "Panel/Floor" actuator motor is not working. All air was blowing out of roof vents (Panel), but this repair can wait (best position for A/C).
2) Heater Hoses were Hot, just like OP. In my case, I learned that the vacuum line had fallen off of the pneumatic actuator on heater bypass valve, near the turbocharger. I also learned that the vacuum line was melted and fused shut from laying on the turbo. So...I had to cut off the bad tubing and re-insert into the coupling to connect to actuator. Now, the heater hoses are ambient temperature back near the auxiliary heater core.

Even after finding the obvious problem with hot water going to the heater core, I felt like the rear air was too warm.

Then, I took it in to a local independent shop yesterday and told them rear air was 'luke-cold' and front was 'somewhat cold'. They checked the charge of the A/C and found I was down about 1 lb of refrigerant (they said I had 3 lb in system, where it requires 4 lb). They charged it up to 4 lb and put in leak detector. Cost about $100 for this.

Well, the A/C is much better, especially when truck is moving. But, it really is not too good when idling and I seem to remember it being much better around town. Yesterday was sort of an early taste of an eastern Oklahoma summer (92F, with humidity over 65%), so maybe I'm just too wimpy for the weather.

I'm of a mind to take it in to Ford dealer to get a second opinion. Maybe the compressor is just not working as well at it once did, or the TXV on the auxiliary evaporator is not opening properly.

 

Yes, those valves tend to get stuck.

 

Interesting thread for me. My '05 is going to a shop next week and that's one if the things that I'm having looked at with one difference. I have plenty of cool air in the rear. I have no heat. And it was cold down here this winter. So that's on my list of fixes. Good reading though on this. I know more now.

 

Yours should be relatively straightforward fix. It is one of 3 things in order of probability:

1) "Blend door". Electric actuator on side of auxiliary unit that pushes air through either aux. heater core or aux. A/C evaporator. Right now, it sounds as if air is only going through evaporator. I'd put 80% on this as it happened to me.
2) Heater bypass valve. Pneumatic valve as shown in picture above. For heat not to work, this would have to get 'stuck' in the closed position, which requires full vacuum. I'd give this 10% probability.
3) Controls. If this were true, one or the other controls (front or rear) may allow rear heat to work. I'd give this 5% probability.

Yes. It does not add up to 100%. Maybe there is something else out there (plugged heater core or lines?).

 

MikeJH,

Did you ever get yours fixed?

My 2005 is getting worse instead of better. I either have a control problem or a leak. Had warm air coming even from the front vents last night.

 

My TXV valve went tango uniform in my '02 which is being replaced...

 

I have that same problem! Did you ever figure it out?

 

Just an update to this thread.

I thought I had a fairly simple problem with A/C. Maybe low on charge, maybe rear expansion valve (TXV) was not performing properly, etc.

Unfortunately, almost everything was broken on my Excursion. First, my indy mechanics found it was about 1 lb low on charge due to leak near Schraeder valve. But... the performance (air temp from vents) did not improve much after getting a full charge. It wasn't too bad on the highway, but still seemed a bit warmish on a hot Oklahoma day.

I took the truck back and the found that the fan clutch was not engaging as it was supposed to. The working theory was then that there was not enough air flowing across the condenser. So, I signed on to have this replaced (part price is almost $500!).

They pulled all the R134 out to replace the leaky Schraeder valve. While evacuated, the pulled out the 'orifice tube' and found it full of metal shavings. Ouch. The compressor was disintegrating!

Long story short. The compressor and receiver/dryer had to be replaced after totally flushing the condenser, evaporator(s) and all lines. I also had them replace the TXV in the auxiliary system. One (1) of the two (2) actuator motors on the auxiliary air handling unit in the back also had to be replaced. Parts came to over $1200 (including fan clutch) and labor was almost $1,000.

Ouch big time.

The good news is that I seem to have 'like new' performance of this A/C system restored. We hope to get another 160,000 miles out of the rebuilt A/C system. And...philosophically--keeping the big rig running in good shape is much cheaper than starting over with a new truck. The upcoming family vacation can now proceed without a mutiny in the ranks.