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05, Can you replace fan switch by removing the head unit?

19K views 12 replies 8 participants last post by  billycolorado 
#1 ·
I purchased a new heater fan switch for my 2005. I am getting the intermittent A/C green light. It really looks like you might be able to replace the fan switch by removing the stereo head unit rather than undoing the console forward to the cigarette lighter panel. This looks like it would give enough room to access the back of the panel and the switch from above, rather than having to pull the entire control panel/cables.

Has anyone tried this approach when replacing the entire heater fan switch?

Thanks for the advice!
 
#4 ·
Hey, the fan switch is the center of the three rotary dials above the cigarette lighter and immediately below the radio head unit. The center switch controls the fan speed, and evidently the A/C compressor.
The switch fails often on the earlier cars. Fan will work, but the green light and the a/c will blink off intermittently. The only instructions I have found show removing the center console, the shifter cover plate,
then the ash tray, then the cigarette holder panel, then the control panel where the three rotary dials reside. You must also remove connectors to the vent doors when going this route. As I'm replacing the
entire rotary switch, if I have a clear shot at the rear of that control panel, I 'think' I can remove and replace the center rotary switch with my new one.
Make sense? Can do pics if necessary.
Thanks!
 
#5 ·
Most of the A/C / Fan unit has a covered plate above it, that I remember, but I'm not even sure how to go about removing that thing. I don't know if anyone has really figured it out since it has hard rods that go into the blower motor, then again, maybe I'm just confused what it is you're still looking to do.

You want inside of that unit?... from the top?
 
#6 ·
Yes, I simply need to be able to release the center rotary switch from above and behind, and slide my new one in while reconnecting the electrical connection. I did find a post tonight by spitfire71 who did replace this switch via this path. The post was from 2009, and was two sentences. Talk about a needle in a haystack!
Thanks for the help. I'll post up my results Thursday.
 
#7 ·
Ok, so here is the final report. Yes, you can replace the hvac fan switch pretty easily by removing the radio.

First, remove the trim piece on the top of the radio over to the passenger side of the dash. There are plenty of youtube videos showing how to remove the head unit. Once the radio is out you'll see a white plate that is the top of the rotary switch plate for the hvac system. The fan switch is in the center.

Remove the fan switch knob from the front of the hvac control panel with a gentle pull. On the back of the panel, now accessible since you removed the radio, there is a plug on the back of the switch that must be disconnected before the switch can be removed from the mounting plate. The tab for this is on the bottom, facing towards the ground. I used a radiator hose pick to press the tab so I could remove the electrical connector. Once the electrical connector is off the switch can be removed. Here is the only issue with using this method for replacing this switch. There are three tabs. You can release the top two easily from the top. The bottom one can only be accessed if your remove the hvac control panel. I chose to release the top two tabs and push the switch out the back of the control panel plate. In doing so, I broke the bottom mounting tab. When replacing the old switch with the new, the mounting of the new switch is not quite as solid without the bottom tab. That being said, I think it is solid enough. If I have any issues, I'll just go back in (only 4 screws to remove) and put a little goop on the bottom of the switch to hold it firm in a way that can still be removed later if necessary.

I have a bad back, and didn't want to have to crawl around under the dash to remove the vent control rods. Those must be removed when replacing this switch by removing the console, ash tray, cigar lighter panel path. Going in from the top is a viable method, but will probably result in a broken mounting tab. So, the top down method is probably not the preferred path if you are able to get to the vent control rods from below.
 
#12 ·
Hi,
I believe this guy has found a decent way... Not real clean, be looks like it works. He's posted a means to remove the 3-knob assembly to replace bulbs, but serves similar purpose:

OK! So, I see a newby can't post links. Try searching YouTube for ...
04-09 Mazda 3 Manual AC control BULB replacement

Posted by 78cwcaldwell


I'll be trying this same technique to replace the rotary fan/blower speed control. AC will not come on unless you really mess around with the knob. Used to be easier. Now getting to be a PITA.

Wish me luck -- Sharky
 
#13 ·
I had the intermittent AC problem due to the fan switch for over a year. I bought a replacement fan switch and popped out the head unit to look at the fan switch from above without removing the entire climate control panel.



I couldn't get any of the tabs to release and knew I would probably break one or more if I forced them. I then took a small inspection mirror and looked behind the switch to find that there were a series of holes on the the back of the switch that exposed a copper plate on the inside of the switch. I took a can of CRC Electronic Cleaner and sprayed the cleaner into the holes while rotating the fan knob back and forth. I let the switch dry for a few minutes and reassembled everything. That solved the intermittent AC problem! This was a 10 minute, easy fix and it's been working great for over a week now.



Wish I hadn't wasted money on buying a replacement switch.
 
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