NC heater/ ventilation issue...HELP!

Technical Area Body, Interior & Styling
2

Hello all,
Ā  Ā  Ā  Ā  Ā  Ā  Ā Iā€™ve had my MX5 about a year I think and right from tne off there were some odd noises coming form the passengers side dash vent. There was something rattling about and with the heater blowing full on and the others blocked up I managed to fish out 2 small plastic toys. Like little swords from a Playmobil figure.

I was left with one more rattle but this one was different. It was much lower down and happened even when the blower wasnā€™t on. It would roll frrom side to side as I went round corners. It was driving me MAD!

Last weekend I thought ā€œThatā€™s it, Iā€™ve had enoughā€.Ā 

I got as much of the dash parts out of the way as I possibly could without going overboard.Ā 
The audioĀ and heater controls.
The shiney panel with the face vents
The glovebox
finally the blower itself.

With this all out I could have a proper fish about andd then I found where it was. Right in the lowest part under a sort of box, which frrom looking on the internet contained the heater matrix
Being VERY careful, I took my dremmel to it and cut a small square out, making sure not to go in any futher than the thickness of the plastic. I made a little door, opened it and TADA!!

There is was, a Lego figureā€™s head, all battered from rolling about for who knows how many years! So itā€™s out, the noise has gone butā€¦

I now have next to NO heat coming out of any vent unless the car is sat still after a drive.Ā 
That means, on my 20 minute drive to work, where it used to be lovely and hot after less than 5 mons or so, now I get to work and itā€™s barely warm. If I sit in the car for a few minutes though, at standstill, I can then feel the heat.

What has happened?
I can only think that during my ā€˜fishing aboutā€™ looking for this rattle, Iā€™ve disturbed something.
The other nugget if information is that when I now move the heater dial from hot to cold, I can hear the flap/valve move but it then clicks a couple of times when it reaches its end point, like itā€™s fighting against something.

Does anyone have a picture showing this valve or somethign that would dirent me to itā€™s location?
Iā€™ve been hunting about but have come up blank.

Winter is coming and this is my only transportā€¦HELP.

Ā  Ā  Ā  Ā  Ā  Ā ThanksĀ 

3

Please put the little man back intact; clearly he was there to shovel coal

4

Presumably the hot air is coming it the hole you cutā€¦

Replace the box?

5

The hole is completely sealed up now, no air is getting out at all.

What Iā€™d really like is an exploded diagram so I can see whatā€™s what.

6

Go to the Mellens website (USA) where all the service manuals are as pdfs, and look at the files for HVAC (Heating Ventilation Air Conditioning). Everything you might need to know and a lot more can be found there.  Bear in mind there will be some left to right transposition on some aspects because it is specific to the LHD Miatas rather than our RHD MX5.  Fortunately most of it is common to both and the principles apply equally.

http://www.mellens.net/mazda/Mazda-Miata-2006-2007/index.html

 

Iā€™m prepared to bet you somehow managed to disconnect one of the plugs to the assorted motors that operate the fan and the flaps on the central box, or did not fully reseat the centre-console panel carrying the control knobs.

Good luck.

7

Thank you very much RichardFX.

Those exploded diagrams were exactly what I needed and from them I think I have found a thread on another forum that shows a picture of the part at fault -Ā 
https://forum.miata.net/vb/showthread.php?t=578926

That flap, I think, is the part that is not fully moving through its full movement range and itā€™s ā€˜clickingā€™ at the cold end of the scale.
I did think that I could ā€˜resetā€™ the actuator or something but Iā€™ve had the dial all over the place with the wiring block for the control in and out, hoping to get it back to where it should be.

Before I even consider taking the dash out, Iā€™ve bought a little borescope off Fleabay to see if thereā€™s anything I can see/do without it all coming out.

Thanks again, great helpĀ 

8

The borescope thing arrived and I did manage to get the camera in there to see the blend door operating but not quite far enough to se its full operation. I could see half of it and the central operating rod onto which the door was mounted. At the top of this rod, outside the heater box, is the actuator (sadly out of reach in its natural position).

I am sure that itā€™s a door to dial mis-match and I need to somehow work out how to get them back in alignment.
I donā€™t want to blindly pull the plug off and on, there must be some way to ā€˜resetā€™ it.

Iā€™m supposed to be going to Europe in it in a coupe of weeks. Iā€™d really like the heater to work :slight_smile:

Ā 

9

I have the same problem as you on my Nc 2009. I dropped half a clothes beg down the de-mister vent and its worked its way into the heater box and jammed the mixer door. I can hear the gears clickingā€¦ Can you please tell me how to identify the place to cut a hole to access the door? A picture or sketch would be very helpful.

10

Thereā€™s a common fault on the Mazda 6 where the flap actuator strips a cog.

This happened on my dads Mazda6,

I wouldnā€™t be surprised if this isnā€™t the same fault., and maybe removing the lego is now allowing the flap to extend beyond where it was prior to said removal.

11

I have the answer hereā€¦Ā  Ā https://www.youtube.com/watch?v=piYDyMaFZc8

Ā 

1 Like
12

FANTASTIC work , just watch the video, some great ideas,

but why /how does a peg get in there ???

BRILLIANT !