Heater control intermittant/erratic
 

During the past week or so I've noticed that the heater control in my '04 RX8 is not functioning properly. If I turn the knob all the way to high, it will almost always produce lots of heat, but if I turn the knob even one click counter-clockwise from high, the heat goes to full cold.

Also, I found that if I turn the knob full counter-clockwise to cold and then back up to some intermediate setting and then don't touch it again, it will probably produce some intermediate level of heating. But, if I turn the knob even one click one way or the other, the heat goes full cold again.

Weird stuff. I'm wondering if there's a loose electrical connection or something along that line. Any thought appreciated.

1.3L

its a recall the dealer has to fix, i suggest going to the dealer as soon as possible as the part probably has to be ordered.

I have the same problem and I've had the recall done. Mine has been doing it for several months. I've had my 04 for 16 months and had the recall done probably a year ago.

I was thinking about going to Mazda North America with the problem. Thats what my dealer suggest I do. I've heard of a couple other people having this problem.

Yeah i had the same problem a year or so ago - the dealer knew exactly what the problem was and even had the part in stock so he switched out the AC controller in about an hour for free.. but he scratched up the plastic pieces on the side of the HU :banghead:

Just happened to mine 2 weeks ago, getting a new control installed tomorrow, about an hour to do.

is it the AC amplifier that you replaced/are replacing? Because thats what the recall replaced.

I had the exact same issue, have had mine replaced twice :(

Same issue here, so she's going in for warranty work.

Which part are they replacing to fix this...is it the knobs and the controls...or the A/C Amplifier??

Yup, I have the same issue. It won't blow cold though, just full blast furnace hot. I guess its alright since its winter now. I need to take it in and get it replaced but I need to find a dealer I trust, since the last one did 1600 dollars worth of body damage to my car.

I beleive the HVAC control unit is what they are replacing. Part number FE01-61-190. I know thats what I need.

Edit: My AC still works if I turn the knob hard and hold it there, so its not the Amplifier.

Sorry to get back late but I work out of the country. We have an 05 RX-8. They replaced the heater control unit in the dash on ours (warranty). I only drove it 2 days after the repair but it seems to be fixed. Won't really know until we get back and truly drive the baby. Sure do miss it as the company vehicle is a Dodge Durango, not even close to the same ball park as the 8. Other than that, 36K on it, many hiway miles, KS to CA and back to KS, many trips to OK. Only needed to do normal maintenance, as usual road dings and wear but it's truly a beautiful machine to zoom-zoom in. Will definately buy another when the time comes.

Yes, the list is very long...think 93-95 RX-7.
theres a lot of recalls on these cars!

Screw that dealer crap, especially with all the custom CarPC stuff I have wired in my dash, there is no way I am taking mine for an oil change let alone let them take apart my console...SO, I just disconnected the actuator arm on the center ductwork, rotated the vent to the heat mode and removed the A/C fuse for winter. Now I have plenty of heat, an I can run 'floor only' heat without the frickin A/C running.... I don't have window fogging problems here in AZ, so don't need the de-humidifying effects in the winter (but you could switch the A/C circuit if you needed). For summer, I will re-install the A/C fuse, and manually flip the vent controller arm to the cool side, and no blasting of heat in the middle of summer.
I also bypass the heat exchanger coolant lines in the summer too, but that isn't needed really.

Its entirely up to you! I can tell you any dealer will look at the custom work on your dash and immediately void your warranty!

out of curiosity, how long did that take you? It cant take less time than replacing the hvac ctrl portion of the dash. half hour tops and free! :)

you can pop off the metal rod connected to the arm on the actuator in like 30 seconds... it takes longer to contort your body to get down there with your needlenose pliers. My dealer wouldn't void my warranty for my CarPC, I have sold 5 cars for him, Mazda 3 GT, CX-9 GT, and three RX-8s.... but I still don't trust the technicians to do any work to the car, at any of the dealers here in my town.

Do you know what the price is for this part? I'm having the same issue but I would like to stay far away from the dealer if possible...

Its about 230 dollars from online mazda parts. You can also check mazmart and see if they have a used one for a better price.

You can also try calling Ray Crowe @ Malloy mazda. Great guy! low price and quick shipping!

what about reconnecting the rod?

Do you work for them??? if so then of course they wouldnt. Sometimes its not the techs but management that decides what gets fixed or not(that bottom line thing).

Techs are just like everyone else, for some its a job like any other...the car guys enjoy it so the effort is there.

Reconnecting the rod is easy as it is a threaded rod, but it is snapped into a white plastic clamshell kind of deal.... And, while it is hanging there, I have attached a foam sticky back piece of tape where it lies, so it doesn't bounce on the plastic housing and rattle....

No I don't work for Mazda, but I mind as well have, after all the friends and family I got to buy cars from them.

I understand about the techs, but I am not willing to take a chance with them, unless I were to meet them, explain things, and generally become a total anally retentive ass-hole customer for them. The one time I had to get the latest flash a year ago or so, they left my car outside without the sunshade for 4 days in the middle of summer, had a very crappy rental truck experience, and they somehow ran down the last quarter of gas to the point of low gas light coming on, and shooed me out the door without giving me any details as to what was done, even after asking (paperwork didn't even list the recall code). This after a 4 day wait? Forget it man. I am happy to buy a shop manual.

+1 :)

If we all get together and write a complaint on https://www-odi.nhtsa.dot.gov/ivoq/Consumer.cfm and list it as a safety problem we can get Mazda to address the issue. I had a RX7 that had the same issue.

it certainly could be a safety problem if you couldn't defog for example on the highway or something...

Repair the Heater Control Unit
 

Just in case anyone does a search and finds this thread, I think I have a permanent seamless solution to most of the problems I see here. Check out his DIY I threw together to fix the A/C & Heater control unit:
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-no-heat-repair-heater-control-158200/

Good luck.