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Blend flap

11K views 42 replies 5 participants last post by  Rekusu  
#1 ·
What ho one and all,

On top of all the other ageing car issues, recently the only interior air is blowing onto the windscreen. OK for the winter but would be nice to be able to blow warm air onto the feet if necessary.

When turning off the ignition, for around 30 seconds, I can hear a motor hunting. Transpires it is the blend flap actuator. Seems there could be one of two issues; the motor is faulty or the shaft has snapped and the motor is searching for its 'resting' position.

Today, managed to remove the actuator and found the problem; broken shaft. The actuator is working just fine.

Photo shows where it has broken.

Image


Hopefully, my solution will work, but only time will tell. The shaft is hollow and a 4.5mm drill fits snuggly. Had to dismantle the actuator to get the black splined part out as it is 'hooked' into the inner side of the drive gear. Made a 4.5mm dia bit of bamboo and have epoxied that into the bore in side the blower housing and attached the broken part onto it. Unfortunately, the part inside the housing is around 15-20mm deep so plenty of gluing area. The broken part only has around 3-4mm to glue so am not over optimistic that my fix will be permanent.

Time will tell. At the moment, I have not replaced the actuator as I am waiting for the epoxy to set overnight.
 
Discussion starter · #2 ·
Update: used the car this morning (actuator not yet replaced) and for whatever reasons, whereas prior to removal, air was blowing only onto the windscreen, now it is blowing from the dashboard vents and therefore, presumably also to the feet and screen. Certainly, it is blowing a bit on the screen but not as much as when the actuator was in place.

So I guess that in my attempts to resolve the issue, I have managed to turn the blend flap a little.

For all you blend flap experts out there, assuming there is a specific 'off' position for both the motor and the flap, so that the end positions are registered, what are they. Should the flap be wound fully clock or anti clock to reset it?

If I plug in the actuator with no flap load, and then turn off the ignition, will the motor reset to its default 'off' position?
 
Discussion starter · #3 ·
About one hour of struggling to fit the actuator onto the shaft, which was still in the heater box. Totally impossible; how could Ford have designed something this bad.

Managed to almost get it fitted but when I removed it again, the splined bit with a hex end came out. It's sooooo easy, but when I removed the actuator, there was no way to get the hex out of the flap as I had struggled to do so.

Fitted to the actuator and did a test run but unfortunately, the actuator continued to run in search mode upon ignition off. When I checked, the hex part was now rotating on the bamboo shaft, which should not happen. So have abraded both parts and trying again with the epoxy.

Image


In the photo, the red arrow shows where the break was. the green circle is one of around six tounges (with little hooks at the end) that fit into the actuator (green arrow). Cannot see why it is necessary as the only way to remove the hex thing is to dismantle the motor. So I have cut them off as they do not contribute anything. (Actually, I cut them off while trying to install the actuator as I though these where preventing the actuator from slipping into place.)

Will try to refit again on the morrow. If it does not work, where can I get the black hex thing as that is the only part I need?
 
Discussion starter · #4 ·
Refitted and my repair appears to be working fine. Air blowing from the vents as it should; upon ignition off, I can hear the flaps resetting but only for around 10 seconds now, as opposed to around 45 previously.

I'm a happy bunny. And best of all, SWMBO does not know so it is not another thing to add to her 'you must sell the car list!!!'
 
Discussion starter · #6 ·
Thanks. Had read so much about the flap being broken and no finding anything about how to repair it apart from a heater box replacement, that I was quite happy to find where it had broken.

Looked at the various actuator on ebay but none had the broken bi, only the actual actuator itself. Decided a visit to the local breakers to retrieve an actuator and shaft, but the best and nearest is no longer open to walk in customers (h&s / public liability insurance issues?) and the other one that is open, no longer has an Mk3 in the yard.

So the bamboo fix was called for. Stupidly, as mentioned above, did not realise that the connector came out of the flap, so glued the bamboo shaft into the heater box flap and the bit that fits into the actuator onto it. I had to dismantle the actuator to retrieve the broken bit as there are tounges with little 'hooks' that lock into place. Now I see the reason is that if removing the actuator, the link is removed with it rather than being stuck in the flap section.

First time I tried it, had the same problem of the motor hunting for its 'resting' position, which did not make any sense until I removed the actuator again.

Then I found that the the hex section was spinning on the bamboo shaft; guess the inner bore is so smooth that the epoxy had nothing to grab. But now I had the hex in my hand rather than in the flap and everything made sense. Tested the flap with a hex key and all moving sweetly. Roughened the bamboo and scratched the inner bore of the plastic hex section and re-epoxied. This time, it seems a good firm fit so yesterday, refitted the actuator and at the moment, all is working again.

Can now look forward to winter and warm air blowing into the cabin rather than full-time onto the windscreen.
 
Discussion starter · #8 ·
Not fully aware of having a condensation issue as the a/c has not been working for a number of winters. Generally the car is garaged so kinda stays warm(ish.)

Having read an article in yesterday's motoring Telegraph, where the advice was to spend the money on fixing the old(ish) car rather than by an inexpensive replacement, that one will not know much about and there is a good chance that it could cost more to repair. I am considering throwing a few hundred ÂŁ at the car (a/c; crank pulley oil seal; all rear suspension links) and keep her running for as long as possible. When I find it, I will give a link.

I cannot find much to dislike about the Mk3; large boot and can fit in virtually anything. Even had two Mk3 doors on the diagonal; can't so that in most cars. It is relativey economical (around 50 mpg); running really sweetly at the moment; I know my way around and can fix virtually anything on it; alwsy passes the MOT and has an emission level not significantly higher than original. What's not to like?
 
Discussion starter · #10 ·
I don' t want to say that my blend flap optimism was premature but......

Hit footwell/Off then Auto and the system resets itself with no error codes. Air blows from whichever vent is active; all seems fine.

But!!!!!

Upon turning the ignition off, I still hear the actuators hunting. Just returned home and in the silence of the garage, times it until they went silent. 60 seconds.

Something is not right but I don't know what. I would have thought the actuators would search as the window motora do, until they hit resistance and that is the stop point.

Can I ask a favour of someone; turn climate control on (don't think temp, fan speed or a/c - Econ is important) then turn off the ignition and time how long it takes for the actuators to become silent? I would like some kind of reference.

Thanks
 
Discussion starter · #12 ·
Thanks; 5 seconds sound about right for the motors to hit the end-point.

However, my optimism is somewhat premature. This morning, just to check, fired up the blower and hit the buttons (cabin/footwell/screen) Plenty of air from the cabin and footwell, nothing onto the screen, even if the boost is engaged.

Obviously, something is amiss and it is almost more annoying not to have the screen working. Have to dismantle it all again. Lucky that I am still sufficiently flexible to get my head and arms under the dash!!!!
 
Discussion starter · #13 · (Edited)
Been spending too long searching the internet. Seems that perhaps the blend flap actuator had been dislodged when I sorta dismantled it and needs to be reset. Appears the normal way of doing this is to hopefully, allow the the actuator to get to the middle position, turn off the ignition, remove the relevant fuse (or disconnect the battery) the try again, Apparently, the actuator will then reset to its max / min travel limits.

But I have to dismantle again to see what has broken this time.

Found this advice; it is not for a Ford but assume it would work for any actuator.

Here are the steps to calibrate a blend door actuator
  1. Slot the car key in the ignition, move it towards the on, and turn the HVAC system.
  2. Move the key to the off position.
  3. Open the hood (bonnet for the RHD guys) and search for fuse #15 in the fuse box beside the battery.
  4. Bring out of the fuse and wait 1-2 minutes for any capacitive charges in the system to dispel.
  5. Slot in a new fuse.
  6. Move the key to the on position. You will now notice that the motor moves as the system goes through the calibration routine. Please don’t turn it off until the calibration routine is completed. There will also be other activities as the door and fan are calibrated.
Running the calibration routine a couple of times will help restore the system to full functionality.

And also this web site:
 
Discussion starter · #15 ·
No. The flaps themselves are not accessible as they are in the heat box. But the three actuators and spindle (the broken bit in my photos) are fan box.

Remove the plastic trim below the steering wheel (three X head on the lower edge / two torx behind the right 'bits and pieces' drawer) and the actuators are next to the clutch pedal.

Found it easier to push the seat back. Also, put a bucket just beside the open door and balanced a plank on the bucket and door cill. Can lay on that and wiggle into a suitable position to sorta see the actuators.

Also used a mirror to see the hidden attachment screws. That is challenging trying to get the screwdriver into the torx head while looking in a mirror and being somewhat inverted!!!!
 
Discussion starter · #16 · (Edited)
Unfortunately, for whatever reason, the same spindle has broken again. Although the gears and teeth inside the actuator are small, plastic / nylon, there is a lot of torque to be able to twist a 4.5mm diameter bamboo shaft.

May be my reset did not work because I have not set it correctly or the actuator is faulty and does not know when to stop!

I have repaired the drive shaft again and oriented the cut-out in what seems to be the correct position but yet to install it. will try a 'disconnect the battery' reset before firing it up. If it snaps the shaft again, I will buy a replacement actuator and hope that is the remedy.

One think I don't understand, very few actuator avaialbe in the UK ebay site, some from US and easy to find many from Eastern Europe. And although tose are reasonbly priced (ÂŁ10 ish) the postage can be around ÂŁ45; does not make sense.

Anyway, the attached pdf is a kinda summary of what I have done, location of the actuators and how the position of the cut-out may(?) be important.
 

Attachments

Discussion starter · #18 ·
The US appears not to 'do' postage, only courier so it is always expensive. As for small parts from Lithuania, ÂŁ48 p&p for a ÂŁ10 part; no way Jose.

Needed a couple of plumbing parts which I could only find in the US costing all of about ÂŁ5. Fortunately, one of the neighbours is Canadian and her parents kindly posted it for only a few more pounds rather than the US courier rip-off price.
 
Discussion starter · #19 ·
Probably going to regret this message and can only hope that I am not jumping the gun, but ..................

Having aligned the little cut-out as mentioned above, I disconnect the battery and refitted the actuator. Bloody hell, the drive shaft slipped in sweetly and most amazingly, the three screws all lined up without any twisting, tweaking or force.

Once screwed up, reconnected the battery and ran the HVAC. Everything seems to be fine (it did last time as well!) with the one exception that upon turning off the ignition, I can hear the blend actuators running (resetting) for around 10 seconds before they turn off. Last time, the dodgy one was running for around 60 seconds as it obviously was starting in the wrong position.

I'm slightly optimistic but time will tell.
 
Discussion starter · #24 ·
Agreed about having a spare part. It is hollow from the factory but does not need to be as mine is now solid (with a bamboo filling)

However, after a number of ignition on / off cycles, I listen closed for the actuator to continue to run but they are all off after less than 10 seconds. So my guess is that things are OK (at the moment.) But it does raise the question, why did the drive shaft break in the first place; can only be because the end position lost its final position, but why would that happen?
 
Discussion starter · #26 ·
When I was working in the film/TV special effects industry, 3d printing did not exist (yet.) What i would have done, fast, strong and could make as many as I would like.

Stick to a bit of wood or perspex, put a length of pipe around the part and fill with silicone. When set, remove the original and pour a two part high density polyurethane foam into the mold. The foam is very high density, no bubbles and pours like cream. Ten mins later, would have a perfect copy.
 
Discussion starter · #28 ·
Certainly way off topic, but a few photos of the sort of thing I was making:


Yours truly with giant East Egg!

1/10th scale kitchen

Geo Location ad for Sony Phones; pin around 2.5m tall

Shop bought toy van but had to make rear doors open/close, paint and apply logos

Gold and rusty keys around 150mm long

Did a few movies bits and bobs as well. All these items were for TV commercials

It was all good fun, boys playing with fun things every day. Only challenge was the deadlines!
 
Discussion starter · #31 · (Edited)
The kitchen was not just me, there was a team on the job. Had to make a bathroom and loft. Was for heating / energy saving before it became the hot topic; the camera pulled upwards from the kitchen, through the bathroom, through the loft, to the whole house, street, town, etc and into space. Most of the later was CG but the closeups of the rooms had to look real.





And since this is a motoring forum, we had to make a Skoda out of cake!!!! The ad won a number of industry awards, but the bosses spent considerable time talking the director out of using real cake. Too many problems; no structural integrity, no access to sufficiently large ovens, would collapse under its own weight; would rot quite quickly in the studio during the one week shoot; good possibility that the vermin would find it over night in the studio. It was finally made with puffed rice, raisins, dried cherries, etc, all mixed with fibreglass resin. Some real cake was used; the ad can be viewed here

 
Discussion starter · #33 ·
Expletive Deleted!!!!!!

Can only assume that the actuator is faulty. Things were looking good for a while but now, I only have air from the cabin and or footwell, nothing on the screen. In fact, hit the screen button or the screen override, the blower fires up and the cabin and footwell give a nice blast.

Guess the drive shaft is broken again. Have ordered one from eBay, coming from Lithuania so hope that it is not faulty. Picture shows actuator and drive shaft so trust that the drive will be with it.

Annoying; you bet!!!
 
Discussion starter · #35 ·
You cannot take all the parts that you 'think' you may need in the future.

I had a fender bender some years ago and needed at least one door. As the breakers had a good car in the same colour (how lucky can you be), I bought three doors (paid for by the guy who hit me!!!) I don't really need three doors, but one of mine is rusting nicely at the bottom and the breaker car was in much better condition.

Having replaced two of the doors, and re-used all my original window / lock gear, I subsequently had a lock issue. Sounded like all the doors where locking but one was not. Fortunately, never had anyone try to get in.

But as luck would have it, I had the spare parts from the breaker door and exchanged them; voila, lock working again. So it is worth holding onto various bits and pieces.