RX7Club.com - Mazda RX7 Forum - AC directional control not working?

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AC directional control not working?

So ever since I got this car from the dealer, (92’ rhd FD) the knob that controls the direction that air blows hasn’t worked. The heat, AC and fan all work just fine. I just can’t make it blow to the feet, face, windshield... ect. How do I go about diagnosing the problem? Thanks!

There is something wrong with your Air Flow Mode Actuator (AFMA), It could be the switch is bad, the actuator is bad, or a linkage is broken or stuck. First move the rotary air flow switch around and listen for the AFMA pushing the flap around. If you hear the actuator then it is good and there is something wrong with the linkage. If there is no sound then it is probably electrical. Here is are the Body Electrical Trouble Shooting Manuals. Use the 1993 one for doing your electrical troubleshooting Page G-41:
https://cimg6.ibsrv.net/gimg/www.rx7...8435fa6fd1.jpg

I had a variation on that problem; no response to a command for dash vent-only airflow but the other functions worked (defog, heater, etc). The root cause in my case was a bad controller board, not sure what the official name is but it is the computer located behind the control knobs. A good used replacement board restored function.

Here is the Heater Control Unit that jza80 was talking about:
https://farm1.staticflickr.com/979/2...35d097b0_b.jpg

And here is the Troubleshooting Flow Chart for your problem, note the bottom right table for the heater control unit test:
https://farm1.staticflickr.com/963/2...9ae9893c_b.jpg

Awesome thank you so much for all the info! I’ve been working and haven’t had much time to mess with it. But yesterday I messed with it and could hear the actuator trying to work when I turned the knob, so it sounding like it may be in the linkage to the actuator?

Yes, if you can hear the actuator motor then there is probably a mechanical problem. Take a look at the metal actuating rod where it attaches to the motor and you might be able to see what is going on.

This may be a dumb question but is this at all possible to do without taking the whole dash out?

You are very fortunate. Opportunity is knocking! You now have an excellent excuse to restore the heater core. Check out all the the fun and interesting things you will learn along the way in this thread. :rolleyes:

I like the optimism^^ haha

Some Great info here guys! My CC comes on automatically when you start the car then, until the car warms up (about 10mins) won't let you change anything or switch it off. Once warmed up everything works 100% it's very random and weird like a ghost in the machine. Yesterday, rather bizarrely, everything worked from starting the car!

Reading this thread, it seems my issues are nothing compared with what others are experiencing.

I haven't even begun to look at the issue yet, but my advice to anyone here would be to check for dry joints on the circuit boards. These cars are now going on 30 years old. If the solder looks dull and brittle then stick a very hot soldering iron on it and dab it with a bit of fresh solder so it looks shiney and new again.

If you have no experience with this sort of thing then leave it well alone lol!

If you are a little more experienced then it's worth using the solder sucker and put brand new solder on most if not all joints.

Again thanks for the info above. Very useful.