Climate control issues?

[smokstac]

I just noticed the fans coming on the radiator this evening and I heard the compressor cycling on and off...even with the vent switch in the floor position. Also when the vent selector is in defrost it is impossible to press the switch changing outside air to recirculate (it switches in all other positions...the car's manual mentions nothing about this so I'm guessing it's a defect).

Sound like a bad climate control cluster or is it something else?

[FE3-323]

are all of your sensors working properly?

[smokstac]

I don't imagine a bad sensor would cause the compressor to cycle on/off when the engine is cold.

[vw.fe2o3]

I just noticed the fans coming on the radiator this evening and I heard the compressor cycling on and off...even with the vent switch in the floor position. Also when the vent selector is in defrost it is impossible to press the switch changing outside air to recirculate (it switches in all other positions...the car's manual mentions nothing about this so I'm guessing it's a defect).

Sound like a bad climate control cluster or is it something else?

Pretty sure the climate controls on our cars by design prevent you from using the recirc option in any defrost mode. Also I think the AC is set up to come on automatically in defrost modes regardless of outside temp. I believe most cars are set up this way nowdays. My Mazda and Mitsu are the same way. My older 93 Mazda has the good old levers, so I can do what I want.
Not sure why you'd have compressor cycling if your vent is floor only. I'll have to play around and see if mine seems to do that. Otherwise, what you're describing sounds normal.

[1Mazda323Fan]

Agreed. The A/C will come on with the selector on defrost, but you should be able to turn it off. At least, I can on my '02. I somehow doubt there's much difference between the 3rd gen model years and trim levels. As to why the compressor comes on when it's on the floor setting....first off, are you sure the compressor is coming on? Not trying to be a dick, just trying to eliminate all possibilities. If it is coming on, you may have a wire touching somewhere, or something has gone wrong with the control panel itself, as you suggested. Does air actually come out of the floor vents when you select the floor option? It may be permanently stuck on defrost, which would cycle the A/C. Oh, and I'm fairly certain that you can't change it to recirc when it's on defrost; as was stated most modern cars don't allow it.

[smokstac]

That's a bummer as I tend to like having the air come from defrost even when I'm not using it to defrost the windshield. This is why I have always like Japanese cars over others...the ability to let me control everything about the A/C, heat, vents, etc.

Definately the compressor is coming on when the A/C switch isn't lighted and the selector is in other positions other than defrost...you can see the cooling fans come on and the compressor's magnetic clutch cycle. I started noticing this when starting the car in the morning...at first I though I was imagining things. Plus you can feel the slight change in the engine while driving. And, yes, changing the air selector changes where the air actually comes out...so that's working as it should.

Looks like I'm going to have to pull the climate controls and see what's going on. Looks like too if I cannot get recirculate while using defrost then I'm going to have to mod that as well.

[smokstac]

I did find an 02 Protege at the Jy today and took apart the climate control system. The A/C and rear defroster are controlled by spring switches very similar to those found on the front of your computer case. The vent selector has a raised cam which presses on a smaller switch when the selector is in either defrost setting....I'm guessing that this is what overrides the main A/C switch and turns the compressor on while in those positions AND disables the switch that opens/closes the outside air.

My theory is perhaps my tiny switch isn't opening up when the vent selector is off defrost and this is what could be causing my A/C to run all the time.

Once I take my dash apart in a few days to install an aftermarket radio I should be able to see for sure.

[FE3-323]

subscribed & waiting to see what you find out

[smokstac]

I took apart a second climate control cluster today while getting an oil pan, spoiler, and fog lights off an 01 Protege. This time I noticed there is a second little switch on the bottom of the first switch that says DEF 1 (the other says DEF 2 on the PCB). This adds more to the mystery as the DEF1 switch closes when the DEF2 is open (and vice versa). There doesn't appear to be any position where both are open or both closed. The metal tab that presses up against the cam on the vent selector gear was broken on DEF1 however (probably rendering it useless for whatever purpose it serves).

Should be interesting to see what I find when I pull mine out.

[smokstac]

This is how the cam on the vent gear operates the AC and recirculation switches. When the vent selector on mine is in the floor position then the AC comes on (first of two small switches is depressed by the cam) but the fresh air/recir switch still allows you to choose (the second switch is open at this point). When the vent selector is in the defrost/floor position then both tiny switches are closed and you can still choose fresh/recir. When the vent selector hits the defrost only position then the first tiny switch opens up (leaving the second closed) and this disables the fresh/recir switch.

I hypothesize that if I take this selector and grind off the cams on the left completely then I should regain full control over my AC and fresh/recir switch.

When I looked at mine when I had the factory radio out of the way one of the small metal springs that gets depressed by the cam had fallen off and was stuck...this explained why my AC was on in all positions. Now that's been fixed and when I have time I hope to mod this spare gear and install it.

[smokstac]

Edit that, my bad: in both defrost positions the fresh air/recir option is disabled.

I'm gonna grab a circuit board next time I'm at the JY and see if I can't remove both switches. Disassembly is quite easy; the hard part is working around the metal cables going to the vents.

[FE3-323]

interesting information. Please do a writeup with your findings!

[smokstac]

Here we go, success! I now have full control over my climate controls. In defrost positions the AC is now off and I can choose between recirculate or fresh air. In short the AC and fresh air/recirculate options work in all positions.

First image is before mod:



This is after removing the cam from the selector...you can now see both switches clearly, see how one has been damaged, and see that neither are operational now.



This is a really simple mod; hardest part is making sure that when you install the vent gear back into position on the black gear that you center the black gear first then install the selector switch in the middle position (there's a spring and ball on the actual selector itself that help in this regard).

[FE3-323]

im having difficulty understandingwhat was changed/modified exactly.....

[smokstac]

You see that black cam on the left side of the black plastic about 4 posts up? I totally removed that so there's nothing that can press either switch now. That's the only thing modified to make the ventilation controls act the way they used to work in the BHA series (and most other Japanese cars).

By doing so I can put the vent selector in either defrost position and now the AC is only controlled by the actual AC switch and the selector for fresh air/recirculate will allow me to choose either position. In other words put the vent on defrost and the AC stays off unless I want it on, and, I can close the outside vent if I'm driving down the road, have it in defrost, and there's someone blowing dust, etc. which I don't want to breathe.

You can see where the cam was removed in the post two posts up. In the top photo you can see where the plastic engages the switches and in the bottom photo you can see the space that results by removing all that plastic on the left. Basically I just took some wire cutters and snipped it all off, then, used a knife to shape it down.