HELP! Rear a/c vent not blowing air!!!!
- Thread starter rhayan911
- Start date
I took my car to the dealer yesterday for this exact problem and they are still trying to figure this out. My service guy took me to the bay to show me this (interior trim was still removed): The tech replaced the motor for the rear vent, but the wierd thing is that when the rear vent housing is NOT connected to the vent tube coming from the dash, the rear vent blows air. When the rear vent housing IS connected to the main vent tube, the rear vent stops blowing air. The dealership tech is waiting to hear back from Mazda for a solution as the dealer can't start swapping out parts without authorization for the warranty work. I'll let you know what the resoution is.
They have to replace something like a selenoid under the dash, near the gas pedal. It also happened to me last summer (no air coming out and sound like if something is blocked) and the tech finally found the problem after couple of hours. I cannot give you the exact name of the part they changed,
they just didn't wrote it on the invoice.
they just didn't wrote it on the invoice.
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- 2008 Mazda5 Touring
It probably controls a damper to divert air to the rear blower.
That is the exact issue I had in addition to a faulty rear vent motor. The kids are happy now.
greatwhitenorth
Member
- :
- 2008 Mazda 5 GS
Does anyone know this part number and where under the dash it is located? Thanks.
Old thread, but since I just worked on it, here goes. It's the rear vent actuator and it's behind the panel right beside the gas pedal on our '08. There is a small metal brace that has to come off with 2 nuts and 2 bolts (both 12mm) then you can remove 3 phillips head screws and it will slide out with some wiggling. That actuator opens a vent door to allow air to the rear blower.
On ours, the actuator motor is fine, it's just not getting 12vdc to move it either direction. So, what I did was hook up three li-ion batteries in series to get close to 12v and energized it to open the vent door. At least we have rear air for the summer. Unfortunately one of the controllers is probably bad which is $$$. I'd rather the actuator have been bad.
I'm going to do a couple more checks per the troubleshooting guide but am pretty sure I know what's going on.
Pics: You can see the black actuator behind the bracket that needs to be removed but a 12mm socket takes care of that pretty easily.
On ours, the actuator motor is fine, it's just not getting 12vdc to move it either direction. So, what I did was hook up three li-ion batteries in series to get close to 12v and energized it to open the vent door. At least we have rear air for the summer. Unfortunately one of the controllers is probably bad which is $$$. I'd rather the actuator have been bad.
I'm going to do a couple more checks per the troubleshooting guide but am pretty sure I know what's going on.
Pics: You can see the black actuator behind the bracket that needs to be removed but a 12mm socket takes care of that pretty easily.
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- 2006 Mazda5 Touring
Thats good info right there! Could you work up a method of opening the damper manually I wonder? Like the outside air/recirculate flap on the main airbox? This tells me that the rear air really isn't any great shakes as all it really does is take air from the main and recirculate it with a fan. Interesting.......
I actually thought about that. You could probably get a string around it and have the panel keep it in position, though the damper is spring-assisted shut.
With it open all the way, it doesn't appear the rear blower does a whole lot. Low speed on the rear doesn't change the airflow at all, high does speed it up some. The front vents still blow great, especially now that I changed the cabin filter which was nasty.
With it open all the way, it doesn't appear the rear blower does a whole lot. Low speed on the rear doesn't change the airflow at all, high does speed it up some. The front vents still blow great, especially now that I changed the cabin filter which was nasty.
Thank you SuperJETT. I have the same problem on my 2010. Using a meter I could see the 12 volts for about 5 sec, but the motor did not move. I then tried 12 volts to the motor and the door opened. Great! My final set up includes rigging two wires on the motor connector. With a Radio Shack accessory connector with push in wire connections, I open the door with a brief connection to my accessory connector on the dash. That opens the door. To close I reverse the polarity , plug in to accessory, and the door closes. No need to keep it connected to 12 volts so I feel safe. Only two of us, but sometimes I need rear cooling.
Now to learn about control modules. That may not be in my future, but I'd like a price.
Thanks again, Marty
Now to learn about control modules. That may not be in my future, but I'd like a price.
Thanks again, Marty
Interesting, I never saw 12v. I have no blown fuses, and that actuator is probably powered off the hvac system anyway so the whole thing probably wouldn't work if that were the problem.
I like your solution. I'll have to dig more into things to see if I can find out which controller handles the actuator. I wonder in my case if just a battery disconnect to reset the computers might help?
I like your solution. I'll have to dig more into things to see if I can find out which controller handles the actuator. I wonder in my case if just a battery disconnect to reset the computers might help?
Don't know if it matters in your measuring, but the 12 volts will swap between the two pins based on the direction command. You may have been on the opposite pin. The voltage will only appear for about 5 seconds. Although I have voltage I suspect the drive circuit can't supply enough current. Still thinking about it so we'll see.
Marty
Marty
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- 2008 Mazda5 GT
Slightly off topic, can anyone explain why heat doesn't come thru the rear vents if it only draws air from the main unit??
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- 2006 Mazda5 Touring
I will posit the theory that the heater cannot supply enough warmth to overcome the amount of air being moved by the rear fan. I see this at work with forced air reheat VAV boxes. If you push too much air across a heat coil you literally "blow" the warmth right out of the air. That and the distance from the heater core to the rear vents may be too great as well....And the heat is coming directly from the heater core to the foot only vents like it does in the pre rear AC 5s