2002 Windstar - Aux heater/ac no control

[boho]

Hi,
I have a problem with my rear auxiliary heater/ac unit. The front (main heat and ac) works fine. But the blend door and the mode door don't change positions when called for on the Aux Climate Control (right rear quarter unit). I always get high heat through the floor vent on the left side of the passenger seat. If I move the main control (driver switches) or the secondary control (rear passenger switches) to COOL, the rear floor vents are always wide open and hot. I cannot get air to the overhead vents or change the temp of the air. The fans work properly from the front and passenger controls. I took off the left rear quarter panel to inspect the blend actuator. Took it apart and no broken teeth or cogs. Put a multimeter on the actuator pinouts and see no voltages on any pins. Checked all the fuses under the dashboard. All OK. Bought a Haynes Manual and they barely touch on the Aux Heater/AC. No diagrams for Aux either. Can't find diagrams for the Aux on the web either. If I had diagrams I could trace this issue. Took out the REM from the right back quarter and opened it. No charring, burns, bubbles, no issues. I don't know if that comes into play here or not. Reseated the connectors. Still no go. I can't see two actuators going bad at the same time. The actuators just aren't receiving the commands. I'm missing something? Any help would be appreciated. Sorry this is so long. I just wanted to give you as much as I know now. Thanks

[12Ounce]

As soon as my '99 Winny arrived, I disconnected the "mode" actuator ... as I never really understood the reason for it, and it always caused constant irritation to folks in the back if the driver made temperature adjustments. The temp blend door was left working.

As far as the circuit is concerned, its made more complicated by the fact that there are aux controls for the driver and aux controls for the rear passengers. About six pages, or more, in the circuit diagram book. If you want to send me a postal address to my private mail, I will paper copy these pages and send to you "snail mail". Or you can try searching Ford Publication "FCS-12255-99".

Of course, your model may be significantly different from mine. Have you tried visiting a Ford dealership and copying their work book? I find there is usually a person who will help a DIY ... for a coin or two, perhaps.

[boho]

Thanks 12Ounce. I just sent you a private email (I hope I sent it correctly) with my snail mail. Thanks for helping, I appreciate this. I will let you know how I make out.

[12Ounce]

Got your mail. It'll take me a couple of days.

The '99 represented a complete wiring change from earlier models. Windstar went through another wiring upgrade a couple of years later, perhaps 2001. So my information may, or may not, be beneficial.

These folks: Books4Cars, show a 2002 wiring book "B02_Wind_Wire" for $25. Don't know if its any good, but these are the folks that I bought my shop and wiring books from. Might be worth it.

[boho]

Hi 12Ounce,
I think you are correct. The difference between these two model years is probably significant. For instance in the 2002 they use a hybrid Function Selector Switch which has (vacuum (Front Mode Control) AND electronic (Rear Mode Control) combined into one switch). I don't know if the 99 has that. Also the 2002 has a Front Electronics Module (FEM) and a Rear Electronics Module (REM) to separate those functions/controls.
If you have already assembled and sent those pages, Thank You so much, I appreciate it. If not then please hold off. I will look into the book you suggested for my year and model. I'm also looking at buying a subscription to Alldatadiy.com. I hear they are pretty good.

I will let you know which one I end up purchasing and how I make out. Thanks 12Ounce for your assistance. It means a lot to me.

[12Ounce]

OK, I will just "stay tuned" for now.

Actually my '99 does have the FEM and REM. I think it was the first model for the "twisted pair" communication cable about the vehicle. But they made changes in a couple of years mostly; I believe, in the fuse and relay layout, probably to save some copper ... but its enough change to be confusing if using wrong diagram. Trust me, I tried! There were other changes I'm sure. I know the relays became more hermetically sealed ... and smaller.

[12Ounce]

...another thing: If you do order a book from that supplier, you might best check to see they actually have it ready to ship. Otherwise, your order may languish in limbo ....without your being notified.

[tomj76]

FYI, the '96 uses vacuum control to determine cooling or heating mode. A rear fan speed determines the amount of conditioned air flowing into the back. Mine rear system malfunctioned many years ago. It was resolved by replacing the vacuum control switch in the front dash. The nature of the problem was heating air was delivered when cooling air was requested. The vacuum control actuates a "motor" that moves a deflector to cause air to move over the rear a/c evaporator rather than the rear heater core. The actuator reverted to the default setting without the vacuum pressure from the front dash selector.

[boho]

Finally, it is done. Almost. Ordered a subscription to alldatadiy.com and bought the Haynes Manual and the Fomoco wiring diagram book. To be honest the alldatadiy.com was the better, and most useful, of the 3. One thing that was curious in all 3 is an input labeled "Low Coolant Level". This is circuit 465 that goes from the Rear Function Selector Switch (connector C951 pin 4 WH/LB) to the REM (C3030b pin 16 WH/LB). I'm thinking what purpose does that serve? Tried to find the origin and function but I can't find it anywhere I looked. The circuit was at 0 volts.

Anyways, after reading many schematics and trying to isolate the problem, I decided the REM was my best bet. Ordered one on eBay and it didn't fix my problem. It made it worse. With it the REM still was NOT commanding the AUX blend door or the mode door AND the blower motor didn't work now either. Sent that back to the vendor and ordered another from another vendor. Put that one in this morning and viola! The AUX blend and mode doors work. I'm happy. The AUX AC/Heater works as advertised. Very cool and very hot. Nice.

When I now measure circuit 465 I have 12 volts. So I am assuming its not really an indicator of "Low Coolant Level" but an indicator that the REM is now able to function. Not sure really.

Now I have one last problem. The front vents, are just barely below the ambient air temperature when set to cool. They will get very warm when set to heat. I am assuming the AC line Tee's off somewhere between the Compressor and the front evaporator to feed the rear evaporator, so I am suspecting a clogged orifice tube in the front evaporator. We'll see.

I want to thank you all for the help and guidance I have received. I truly appreciate it.

[12Ounce]

I had to look. My electrical book is full of corrections I have made over the years. I think the engineers hand off "hard to read" notes to the graphic department ... and then never check back for correctness.

BUT; my 465 is a WH/LB conductor that only goes between the REM and the REAR AUX A/C CONTROL. Connector #C341-16, "rear aux temp input" ...to connector #C930-3, "rear aux temp output".

No mention of coolant.