Solution To Flickering Fan Speed 2 Or 3 A/C PART 2

I didn't pull it out and stick the multimeter on it yet today, since it's 130 in the garage during the day, but I drove around a lot and it was steady on 2 and 3. It turns off in between numbers on the way up but not on the way down. Yeah, my worry is that my new connectors aren't any better and I just pushed the problem downstream, but we'll see.
So first hot day of the year today, and the A/C didn't flicker, it just refused to turn on at all in 2 or 3. I couple sweeps and it came on but not steady. 1 and 4 just fine still. So it's more to do with the sweeper itself than the connector since mine are all gold now. It is such a terrible design.

I don't like the idea of having another little box behind my bezel, but I think that's the only good solution for now.


Yellow Mp3 #1315
yellow mp3
Just did and all the numbers light up no flickering and AC is ice cold .....
Mini heat gun (pink ftw) $2.76
Glue sticks $2.39
AC in a Texas summer priceless!

Thanks to whoever did this write up!
2004 Mazda 3
After trying the described method the problem persisted, so I fixed my flickering AC by a different method.


The problem was in the switch itself. Once you take out the Stereo, you will get access to the switch - it is being held by 2 clips on top and bottom - use a flat screwdriver and the switch pops and you take it out from the housing - then you can unplug it from the connector.

Then using a small flat screwdriver open the switch and clean the brass connectors inside the switch from the oil (i recommend using some isopropyl (or any) alcohol).

Then follow the steps backwards - close the switch, push it back in the housing, plug in the connector. Test your AC before you reassemble the Stereo.

The problem was that the switch is over-lubricated oil got onto contacts. The problem is again - not in the plug but in the switch itself.

Enjoy the free solution to the problem!
2004 Mazda 3
It is not oil, it is dielectric grease. It wasn't what was causing the bad connection. The problem comes from corrosion on the switch and if you didn't recover the switch terminals with grease they will corrode again very quickly.

The only permanent solution is adding a relay per these instructions.
I agree - i did not do my research. I guess the solution is to clean and perhaps lightly sand the contacts and then re-cover with dielectric grease. Should last a couple of years...
I did exactly that (sand and recover) and it only lasted until the next summer before it started flickering again. I then replaced the original harness with one I made out of gold connectors and that lasted until the next summer. The relay is the only way to permanently fix it.

I don't really like the extra box back there, but the other way is replacing the entire blower resistor pack with individual relays. The resistor pack is such a dumb waste of power. We've had pulse width modulators for several decades, but Mazda decided that turning electricity into heat was better for their bottom line.
Protege5 2003
The resistor pack is such a dumb waste of power. We've had pulse width modulators for several decades, but Mazda decided that turning electricity into heat was better for their bottom line.
I doubt the existing fan motor would be at all happy with a PWM input. (The only PWM motors I know of are dinky, for computer cooling.) The motor is a big inductive load and putting a high frequency high current square wave into it seems like a poor idea. Rapidly shut off the current into a coil and a huge voltage spike results. I don't disagree with your basic point - it should be possible to control a blower efficiently, but it isn't likely to be as simple as throwing out the resistor pack and using a PWM driver. Can't really fault Mazda for the resistor pack, as that method seems to be pretty much the industry standard. Do you know of any (production) car that has eliminated the resistor pack?
Yeah, this is true. I haven't dug deep enough into my other cars enough to even find out. I would assume it is pretty common still, why fix what's not that broken?
2003 Mazda Protege ES
I tackled this job today as my previous attempt to just tighten the connections lasted only a month or so. Soldered the connections together and the initial results are encouraging...solid A/C light through all the fan speeds. Thanks much for the idea and the instructions!


2013 MS3 w/ Tech
I'm about to tackle this project...
My fan speed 2 and 3 are completely dead, and 4 flickers most of the time it doesn't work aswell.


2013 MS3 w/ Tech
Big freaking CHECK off my list... This took more than 10 mins, once I figured out how everything was clicked and held together it went smoothly. I got it done with some screw drivers soldering gun and a hot glue gun. All 4 fan speeds work now instead of just 1 and a halfassed 4. Thank you for the great write up.
Mazda Premacy 1999
Hello, unless I missed something, I dont believe I read this issue.

I have been having all the same flickering issues for some time now. My A/C only works on the Number 1 setting. After reading this thread, I pulled apart my console to pinch the connectors for a temporay fix. Upon disconnecting the switch form the connector, I revealed this. See attached Pic. Does any1 think it could be a problem with the Blower Motor Resistor. I read a little about this in other forums.

Uploaded with
Hi I have a 1999 Mazda Premacy and have found these threads really useful. I have the dead A/C and fan speed 4 issue too. I will be getting a new reisistor pack and hopefully that will at least get all my fan speeds back. I can't seem to find part numbers easily for the resistor but it is the slim version with 4 in line wires which are blue and yellow.

Looking at your photo and looking under my dash I have noticed that the area around the Air conditoning blower seems to get a certain amount of condensation which has cuased corrosion to the bottom of the blower unit. Maybe this condensation has got into your connector as it looks to have a rust colour to it?

One other thing I'd like to add regarding the DIY fix using resistors connected into the back of the where the radio goes...........the resistor pack is deliberately placed in the air ducting to allow air to blow over it and keep it cool ( I guess this is before where the air gets heated????) Anyway wouldn't the resistors behind the radio thing allow them to get hot and fail prematurely? Just a thought.
Protege5 2003
Anyway wouldn't the resistors behind the radio thing allow them to get hot and fail prematurely? Just a thought.
The resistors in the fix are on a sense line to the controller, not inline with the fan. They have high enough resistance that the power dissipated there is minimal. A short circuit on the wire from the resistor pack to the resistor might heat up that wire, since it would take the resistor out of the circuit. That could potentially happen if the sense wire insulation rubbed through on a sharp metal edge. So be careful when routing those wires. (Or any wires, shorts are never a good thing.)
Hi, I know, I am bringing up an old post....please don't kill me!

I am new here, I have been on ClubMazdaProtege for several years now. I have been reading a lot on this AC flickering problem on other posts on Mazda247.

I just wan't to know, If I change my HVAC with the revised version (The good one), will it fix the problem? ( Or is the problem still present even with the good module?