Why would PO do this? Air control motor.
 

In previous posts I pondered why the heat was always on in this car. Took the dash all apart this weekend, enough to remove the logicon, assuming it was probably the culprit.

After removal, I noticed the control arm from the air control motor was hanging loose. After removing some additional duct work in the drivers side footwell, I saw that the arm had been purposely un-hooked, and the valve on the heater core had been wired open, pemanently, allowing for heat at all times.

I removed the wire, and reconnected the control arm. I then replaced the logicon, and now everything functions as designed.

Can anyone think of why the PO might have done this?

Also, while re-assembling the dash, I dropped one of the long plastic demister vents. WOW, what brittle plastic! It hit the floor and shattered, literally, like glass. Can I get a replacement somewhere, in grey??

Logicon is probably bad, so the mechanic/previous owner hacked it. Pretty common. My entire heater system looked like this when I bought my car...

I thought the logicon would be the problem, too. But when I got it all back together, all functions of the logicon seem fine. Maybe someone replaced the logicon, but forgot to remove the wire. I don't know, just seems pretty strange. Maybe the PO was really cold blooded.

Yeh, those vents are CRAZY
Once I put a WIRE on one by accident and it SHATTERED. Took a while of supergluing, but it looks stock . . . :D

yea the old mazda plastic gets very brittle after a while. Kinda sucks dont it :p:

i swear 98% of my interior pieces are superglued back to there original state

Everybody has the same problem with the interior plastic that has been exposed to years of UV rays coming in, the plastic most exposed is, of course, the most brittle. So going to a junk yard is not a good solution.

Your local Mazda dealer, and perhaps some internet sites, can supply you with new demister vents for the dash for about $25.00 a pair. You'll spend at least that on the super glue to keep them together. I finally gave up on trying to keep mine glued up and because they were so brittle I never knew when they would fall apart again, after a while they never seem to fit the same.

Anyone have a source of metal, powder coated replacements? I don't know why Mazda has never gone to stamped metal for vent material.