heater problems

[fornarog]

Any advice re: this problem with my 99 windstar is appreciated.

Recently, a problem with the heater/ac system has started. There is a steady (1-3 second interval) "thump" (like the noise when you change from zone to zone) coming from the center of the dash, just behind the ac/heat controls. This sound happens regardless of whether the system is on or off, and there is no change between the different zone selections (A/C, floor, defrost,...) If you slide the temperature selector from Hot to Cold, the thump is replaced by a clicking. The temperature selector does not have any resistance to it, and feels like it is sliding freely.

Only cold air is blowing, and it will blow colder when the temp selector is moved to cold, but there is no hot air blowing at all.

Any ideas on what this might be, or how to diagnose the problem?

Thanks

[wiswind]

I do not know a answer to your question....but will point out a couple of things to consider when troubleshooting your problem.

Heat.....The coolant ALWAYS flows through the heater core....regardless of any Temp. , fan, or airflow selection.

When you move the Temp. selector from cool to warmer settings.....a signal is sent to move a "Blend" door to move more or less air from a passage that contains the heater core.
In other words....the heater core is always hot....you select how much air will travel over the hot heater core.

The Selector knob determines where the air will flow....defrost, dash vents, floor......and also for MAX air conditioning and regular air conditioning....how much outside air is drawn in.
This is controlled by another door that I will call the "selector" door.

On my '96, Air vacuum from the engine is used to drive many of these functions. The air vacuum originates from the back of the upper intake manifold.....and there is also a "resevour" to hold a constant amount of vacuum to maintain door position when the engine is OFF.

I have not had to mess with my heat / air conditioning controls.....but from reading here....the blend and selector doors can be a pain to get at.

[12Ounce]

In addition to what Wiswind says:

The noise you hear is likely the actuator trying to move the blend door. On the '99 the blend door actuator is all-electric. The actuator is just in front of the radio... you can usually get a peek at it without removing anything by looking up from the floorboard.

On the '99 there is usually one of two problems:

Problem #1. The blend door actuator has gone "belly-up". Not the worst job in the world to replace, but it will ruin a long afternoon. Some folks have disassembled and repaired the insides of the actuator. But You can get an new up-dated actuator from Ford for about $50.

Problem #2. The plastic blend door has broken. Not all break in the same way, but usually its very bad news. When you investigate the problem #1 above, you will determine if the blend door is broken. Ford has a $1200 - $1300 solution ... as they replace the whole ac/heater plenum assembly ... much labor. I have discovered a way to cut the plenum in a "safe" fashion, and remove/repair the blend door.

Do some investigation and let us know what situation you have.

[fornarog]

I found that I can position the temp control lever in one place (warm) where the thumping stops and there is no clicking either - the "thumping"is when the lever is towards warm and clicking is where lever is towards cold.


I reached my hand up under the dash and felt something turning in rhythm with the thumping, it seemed the the end of a rod or something, and it was just barely exposed from inside a plastic "box". It was turning in a "graduated" movement, approx 5-10 degrees at a time, somewhat like the second hand of a pulsar watch.


Greg

[fornarog]

Twelve Once,

Thanks for your reply!

This weekend I pulled the radio and heater controlls out - what fun!

The noise is coming from inside the black plastic "ductwork" I assume the AC/Heat plenum - located behind - actually forward - the white plastic box - actuator??? - with the post coming out of it. The post appears to be turning, but it is hard to tell for sure with everything disconnected.

I couldn't go further without removing a large part of the dash and ran out of time.

Does this give you any more info to diagnose the problem and recommend a fix? I DEFINITELY cannot afford the 1200 to replace everything.

THANKS!!!!

Greg

[12Ounce]

fornarog

You are getting close. Once you get a little more space, you can see if the actuator (white plastic ..a little larger than a pack of cigs) is actually "actuating". Two, or three, screws is all it takes to remove/replace the actuator.

While the actuator is removed, if you see the female square hole (that recieves the actuator) and if you can turn this "blend door" approx 90 degrees, stop-to-stop ... you, my friend, are a lucky person.... you only have the actuator as a problem.

Get back to us with results.

[fornarog]

12 Ounce

Thanks! My fingers are crossed!

[windwoes]

[quote=12Ounce]In addition to what Wiswind says:

The noise you hear is likely the actuator trying to move the blend door. On the '99 the blend door actuator is all-electric. The actuator is just in front of the radio... you can usually get a peek at it without removing anything by looking up from the floorboard.

On the '99 there is usually one of two problems:

Problem #1. The blend door actuator has gone "belly-up". Not the worst job in the world to replace, but it will ruin a long afternoon. Some folks have disassembled and repaired the insides of the actuator. But You can get an new up-dated actuator from Ford for about $50.

Problem #2. The plastic blend door has broken. Not all break in the same way, but usually its very bad news. When you investigate the problem #1 above, you will determine if the blend door is broken. Ford has a $1200 - $1300 solution ... as they replace the whole ac/heater plenum assembly ... much labor. I have discovered a way to cut the plenum in a "safe" fashion, and remove/repair the blend door.

12OUNCE,
I'd be very interested in hearing how to cut the plenum to remove the blend door.
The actuator in my 1999 Winstar is working fine, but the blend door is definitely broken at the D-shaped slot. I removed the lower half of the plenum and dropped the heater core down just low enough to get my hand in: brought back a 2" piece of black plastic. Basically broke right through the "D" I assumed I would have to remove the heater core entirely to get the door out. Any help would be appreciated.

[fornarog]

Originally Posted by fornarog

12 Ounce

Thanks! My fingers are crossed!

12Ounce -

It was my lucky day, the actuator is shot, but the door is fine. I "set" the actuator to stay hot and put it back in - after disconnecting the wires to it, so at least we'll have some heat that we can control by turning the unit on/off. Only problem is now the zone selector isn't responding, it is set on defrost. I hope this will correct itself when I replace and hook up the new actuator.

You mention an updated/better actuator, how do I get this instead of another one of the original?

Thanks for you assistance.

Greg

[12Ounce]

fornarog

Go right now and buy a Lotto ticket!

Any actuator (XF2H-19E611-??) you get from a Ford dealer will be the latest and greatest. If you have the rear ac and are willing to give up the "mode" (up/dwn) function in the rear... you can just disconnect and steal that actuator. Your model has three elect actuators that are all the same part number.

EDIT/UPDATE: Ford is NOT using the same part number for the three actuators (on vans with rear heat/ac). Therefore the rear actuator/motors are probably not useable up front.

[12Ounce]

windwoes

Don't waste your money on the Lotto.

Yes, the heater coil has to come all the way out to get access to the bottom of the plenum for cutting. By the way, I think I remember one or two screws being at the front (against the firewall) of that plastic distribution "pan" that goes below the heater coil.

If you want to send me a private message and include a postal address, I can send you a few paper copies of the images I made while doing the repair.

Keep up with that piece of the blend door. You must repair the original blend door. Even though Ford has re-engineered the blend door--- the only way you can buy one is inside an entire new plenum assembly.

[12Ounce]

windwoes

You are correct. I took a look at the old photo of my repaired blend door and I see that the hole is, indeed, "D" shaped ... not "square" as I wrote earlier.

[bobzinger]

Man I'm so glad I found this thread. My 99 Windstar has the exact same problem. Thumping and clicking. The heat even worked for a while...if you could put up with the thumping. Now nothing works but the thumping is still there.

Does anyone know if this is caused by a shutoff switch not actuating in the actuator...or if the blend door is trashed? It seems to me that something has to tell the blend door when it's at the end of it's travel, and maybe that something is outta whack.

Anyway...I hate my 99 Windstar, and can't wait till we can afford another vehicle. To date we've spend $1000's on intakes, power steering, rack and pinons, etc.

Bob

Originally Posted by fornarog

Any advice re: this problem with my 99 windstar is appreciated.

Recently, a problem with the heater/ac system has started. There is a steady (1-3 second interval) "thump" (like the noise when you change from zone to zone) coming from the center of the dash, just behind the ac/heat controls. This sound happens regardless of whether the system is on or off, and there is no change between the different zone selections (A/C, floor, defrost,...) If you slide the temperature selector from Hot to Cold, the thump is replaced by a clicking. The temperature selector does not have any resistance to it, and feels like it is sliding freely.

Only cold air is blowing, and it will blow colder when the temp selector is moved to cold, but there is no hot air blowing at all.

Any ideas on what this might be, or how to diagnose the problem?

Thanks

[Windywoes]

Originally Posted by bobzinger

Man I'm so glad I found this thread. My 99 Windstar has the exact same problem. Thumping and clicking. The heat even worked for a while...if you could put up with the thumping. Now nothing works but the thumping is still there.

Does anyone know if this is caused by a shutoff switch not actuating in the actuator...or if the blend door is trashed? It seems to me that something has to tell the blend door when it's at the end of it's travel, and maybe that something is outta whack.

Anyway...I hate my 99 Windstar, and can't wait till we can afford another vehicle. To date we've spend $1000's on intakes, power steering, rack and pinons, etc.

Bob

Like it says above, probably the actuator. i could take mine out w/o removing the radio. Not even a 1 hour job. Test the door to see if it swings free. If so, the new actuator is about $50 at the dealer. easy to install. Now read '99 LX 3.8l Bad Engine Noise Identified and you will see what i recently have gone through with this marvel of poor engineering and manufacture. I could give you also a long list of problems I have had. I don't call myself Windywoes for nothing.

[timechief]

I found this thread to be helpful in solving my heater problem. I used it as aguide, but still fumbled around quite a bit before getting to the root of the problem. I would like to share details of what I discovered during my repair.

I replaced the actuator. While it was off I moved the internal mixing door in the "D" slot with a screw driver.

Ultimately, the problem with the acuator is because teeth have been stripped from the smallest gear on a compound gear wheel (a gear with a littler gear aroung the shaft), smaller than a dime, and probably worth less than a quarter. You see stuff like this in kids' toys. I paid $56 for a new actuator and tore into the old one to discover stripped teeth. Had I brought the vehicle to the dealership, they probably would have replaced the whole heater system for $1500.

The rhythmic thumping is the result of the mixing door, which lays on the heater core in cold mode, being lifted slightly and then dropping back when the missing gear teeth go by. The clicking is the sound of the actuator itself when the gear teeth are missed and the circuitry doesn't know to stop the turning.

I would advise anyone who experiences these characteristic sounds coming from behind the fully electronic heater control panel, to not freak out about something being wrong with the internal and seemingly inaccessible mixer door, and simply replace the actuator.