2001 Windstar - no rear a/c

My rear cabin a/c stopped a few weeks back (air is luke warm). The rear cabin controls seem to work fine in that they move the air output between the roof and floor vents as I change the temp and mix the air as well. The front cabin a/c blows extremely cold air.

I just had the a/c compressor replaced and system recharged about a month ago now. The front blend door was replaced last year when the system refused to blow hot air.

To date I've pulled the rear cabin contols out to check for vacuum pressure but there is only electrical connections. I've pulled the cover from the rear heat/ac unit to check for vacuum leaks but can't find any hoses to check. The blend door actuator works fine as I've mentioned but the air is luke warm.

The rad hoses (?) on the rear unit are extremely hot to the touch and have left burn marks on the unit cover insulation. Is this normal? I assume I need to begin checking for vacuum leaks, probably with the front cabin control unit and move on from there.

I have read through a number of threads on this site but can't seem to find one related to the rear ac unit like this. Any and all help is appreciated.:banghead:

Ok, my front dash is apart and I've exposed my vacuum lines on the control module. Anyone know which color is used for the rear ac unit? And, I take it I can pull all the vacuum lines off together. They appear to have a clear plastic mount holding them all together. Also, I've had zero success in finding any vacuum lines attached to the rear ac unit. Ideas on where these may be hiding?

I confirmed that the temperature control settings, both front and rear, do change the air output location, i.e. floor for heat, roof for a/c, both vents for mixed air.

The only problem that continues is the rear a/c is not blowing cold air. Thoughts?

Hi
I don't have experience with the "newer" models. Mine is a '96. But......I would imagine the system has not changed much. You talk about the blend door actuator - I assume you mean the rear? In '96 it was all hot (floor) or all cold (roof). I believe in later models you had a "blend" capability as you describe. If you are still getting cold in front, warmish in back, I would think you either have a blend door problem still, or that the rear evaporator has a problem. To my understanding, the rear evaporator is really a separate system - the warm liquid freon from the condenser arrives there and passes through an expansion valve to produce cold gas for the rear evaporator. If your rear evaporator is not getting cold, then I think you possibly have a blockage at that expansion valve (again I'm coming from a '96 knowledge base, but I bet the engineering is similiar). Additionally, you can (with the system up and running) check the heater/A/C lines under the left side of the van. You should have 2 heater lines both hot, one hot A/C line (supply) and one cold A/C line (suction). That would give you more information too.

Good Luck

Busboy4, thanks for the reply. I was wondering about the rear evaporator as you mentioned. I first wanted to check the vacuum on the front control switch, which I just completed. Results are: at idle operating temp the black vac line holds at 20" hg, all the others are 0. While idling I jumped my black and orange lines to get the front dash blowing the ac. This worked so I checked the vac with the engine off. All lines (blue, orange, yellow, green, and red) held vacuum up to 25" hg. The black line could not hold vacuum with the engine off.

I also tried to track the vacuum lines to the rear unit. After removing all the rear panels and the back half of the roof liner I have determined the rear unit is electronically controlled (or the vacuum lines are well hidden). So I believe I am back to your thought about the rear evaporator.

At operating temp my heater lines under the left rear of the van are extremely hot to the touch (probably normal) and they are hot inside the rear cabin at the rear unit. In fact they are so hot that I noticed the rear left panel insulation has two burn marks from those hoses.

The ac lines under the van are not cold to the touch. The smaller diameter of the two leads to a bell-like apparatus inside the cabin at the top of the rear unit. This apparatus, while at operating temperature, is very cold and has condensation on it. The tube continues on and enters a plastic compartment above the rear blower. The larger of the two ac lines enters into the same plastic compartment but at a different location, also at the top. I did notice that where each of these metal lines enter that there were leaks where the black goopy stuff was not packed in around the lines. I went ahead and repacked the black stuff (no idea what its called) but this didn't help or hurt the air temp.

Not sure if the bell-like apparatus I metioned above is the evaporator or expansion valve. Also, I checked the drain tube for the same plastic compartment and it is clear. Any way I can check the evaporator and expansion valve? Thanks!

Wow

Scratching my head with you. Since you have a cold-to-the-touch freon line inside at the back unit, I'm going to assume for the moment that the rear evaporator is getting cold. If that is true, then I would think you are either not getting airflow through the evaporator due to clogged fins, or your blend door is not really working properly and some of the airflow is passing through the rear heater core too. Since you do have a cold freon line I am also assuming at this point that you have normal freon flow through the rear unit. I could be wrong on all accounts. However making those assumptions for the moment gives you a direction to go : check the rear blend door and make sure it is moving - I think I have heard of the linkage breaking internally. The actuator goes back and forth, but is really accomplishing nothing. You will probably have to remove and/or disconnect the actuator so you can manually manipulate the blend door linkage (Of course I am also assuming this is possible). Beyond that, I would think checking the evaporator for flow would obviously require taking the rear unit apart to visually inspect it, which may be too much.

One oddball thought: Shadetree technique for proper freon charge has been "equal temp on the freon line into and out of the evaporator." If the line out is warm freon charge is likely low. I would think it unlikely that your front unit would be working top notch if the overall charge were low, however since we are grasping: How much freon did they add after the compressor replacement? I will have to look up the quantity, but if memory serves, the '96 with rear air is around 31/2 pounds.

Got your PM But I see you made it through the stereo removal. I have a 2001 as well but never messed with the rear AC yet except for the rear Control but it still does not work. But I can still adjust from front.. Good Luck on what you find and post back for later help for someone else. Good Luck!! Gary

Quick question. I am going to pull the cowling (spelling) off what I believe to house the blend door. This compartment sits on top of the blower motor and has 6 sheet metal screws holding it in place. If this has the blend door, that I hope to be the problem, then what is the apparatus called that is actually directing the air flow in the rear? Is this an actuator? I can see it sitting between the air vent and the vehicle skin and is nearly square in shape and thin. More to follow.

Quick question. I am going to pull the cowling (spelling) off what I believe to house the blend door. This compartment sits on top of the blower motor and has 6 sheet metal screws holding it in place. If this has the blend door, that I hope to be the problem, then what is the apparatus called that is actually directing the air flow in the rear? Is this an actuator? I can see it sitting between the air vent and the vehicle skin and is nearly square in shape and thin. More to follow.
On the temp control it was called temp control motor at the dealer. I took the part in when I found out it was my problem... Now in your case not sure what you are looking at but if its electronic control it would be a motor if it vac control it would be actuated from what I understand.. Although my door locks are control by motors they tend to say actuated. But if you find that to be your problem I would just carry the part to the dealer. I am sure there the only ones to carry that part.. other than a junk yard..

Just returned from checking the blend door. I removed the ducts and observed the blend door operating in full motion. I then removed the blend door actuator and operated the blend door manually, but did not gain any additional range.

I also removed the cowling for the rear drier/evaporator/whatever it is. Looking inside made me quickly realize I probably don't have the requisite experience to proceed unless any of you have some shadetree instructions/guidance to help me from here. I'm not about to mess with emptying the freon and recharging the system. Let me know your thoughts from here. Thanks.

Well from what you have done there no problem with throwing in the towel. I come to find out with the AC unit,its easier to take to a good shop and let them do a check on it. Now if they explain the problem and you want to replace that part and take back to the shop for a vac and leak test then the final freon fill up they should understand. If they have to replace the part they are going to charge a little more for that part plus labor. But most compressor replacements I have done on the AC along with a new drier. In my case it ran about 80.00 to do this not including the parts. But it was the best way because i dont have the equipment to put freon in a dry system. But I think in your case your compressor is fine its something in the rear causing your problem. I do think the Windstar takes more freon than a regular car so the price may be a little higher.Not sure on this but from what I see on some post it looks that way.. But in my case if a AC problem occurs Ill replace what ever it is and let the shop put freon in. I have put freon in when a system was low but not empty or at least all the way.

Ok. The final result was a trip to the repair shop with a prognosis of a bad expansion valve. Seeing how I don't have the equipment or experience to evacuate and recharge the freon system I guess this worked out. Total cost $270.00, the learning experience...priceless.

In all seriousness, thanks for the assistance; not just for the help in my thread but for everyone who contributes to this website with their experiences and final outcomes.

You all rock!

Whats an expasion valve? Where was it?

Whats an expasion valve? Where was it?
Its inside the High Pressure Line.. If the system is dry you need a quick disconnect tool to remove the line. If it not dry you need to take to a shop. This should not be a too pricey replacement.. Its kinda like a filter.. Just make sure its you problem first..

Whats an expasion valve? Where was it?

5greenmonkies, glad you got it worked out, and thanks for the play-by-play as I know we all picked up some good info. I think your $270 sounds pretty fair.

As to the quoted question, I just wanted to expand (sorry, I'm a little punchy):

The "front" system has a fixed-orifice tube in the refrigerant line leading to the front evaporator. It is inside the line, under the hood prior to the firewall. I think the rear unit must use the expansion valve instead because of the type of refrigerant hose involved - which is aluminum tubing versus the more flexible re-inforced rubber of the front system. The rear expansion valve is located on/in the rear A/C unit just above (above the floor that is) where the rear heat and A/c lines enter the van at mid-way back on the driver's side.

In both cases (orifice tube or expansion valve), warm, high pressure freon enters the device and is allowed to expand rapidly, lowering the pressure and temperature producing cold gas that flows through the evaporator and back to the compressor via the suction line.

For what it is worth, the older vehicle A/C systems like my old '66 Chrysler, used an expansion valve.

Regards