Hello my Mustang family....I have a 2008 Mustang GT, which I bought brand new back in 2008....I've recently started noticing when my a/c is blowing the 2 middle vents cut off and it switches to the defrost mode?? The 2 outside vents work fine, so I took it to the Ford dealership and based on their diagnosis and code, I was told the a/c control module is going bad, but check this out....the advisor tells me the part is no longer manufactured by Ford and is discontinued!!!! So I asked well what do I now, he just told me hopefully it's a glitch and it will work itself out or trying finding one on the internet...needless to say I was super disappointed....bc I can't find this part/module anywhere...has anyone had the same issue? If so what was your resolution?

part # 8R3Z-19980-B

link to the module
https://www.fordpartsgiant.com/parts...z-19980-b.html

 

Yeah, after writing a thing of epicness regarding the system, let me just say it this way: What you're describing? Unpossible. Utterly. Doesn't happen. Physically speaking, under normal circumstances, that set of criteria is not a thing that can be taking place.

The reason is if the defroster is fully on, none of the vents get air. Now, the little air vents on under the dash for the windows, yes, they get air, they're used to defrost the side windows. If that is what you mean, then that's what you need to tell us, because the middle registers not having air but the outside two do? That's not how the system works, or is plumbed. If the outsides are getting air, the inside ones are getting air.

Unless a critter made a nest in there or something like that, then your scenario can happen. It's a blockage of the center two vents, and/or the critter has the defrost door down/open part way, so that's how you'd get it.

So if it's the little vents, then it makes sense. It's supposed to do that. And in that case, I'm not completely convinced its the A/C controls, but maybe the defrost door actuator. I want to say fail mode is defrost, but maybe I'm wrong.

You can find the controls online, here's an ebay search...https://www.ebay.com/b/A-C-Heater-Co...45/bn_87350741
You could also go to a salvage yard and get one there maybe.

The actuators you should still be able to get, if it's that.

I'd be inclined to get a teeny camera on a bendy stick and shove it down the vents to see what's going on, myself. It just doesn't sound right at all as described...

Please do update if you have more info after reading.

Hope that helps, and welcome to the forums!

 

@houtex ..Little harsh on the reply,.....not sure how else to explain it other than my initial post....and I'm pretty sure I noted that I took it to Ford and explained to them the same thing hence my post in regards to an a/c control module issue, at any rate thanks for your input I think, no need for you to reply pertaining to my issue going forward.

 

I'd check car-parts.com for a junkyard near you and ask them about it. Good luck.

 

If the dealer did a diagnostic code check for the Climate system what code/s did they get? I feel your problem is either the drivers side Panel/Floor Door - Mode Door Actuator or the passenger side Defrost Door - Mode Door Actuator, There are four mode actuators, one on drivers side and three on passenger side. The defrost door actuator should be the upper one on the passenger side, while the lower one is the blend air door actuator and the air inlet actuator is the one far right near kick panel.
If you feel the need to change the A/C control module just get one from the junk yards. I had bought one years ago from an 08 for my 05 and it worked fine. You just have to find one that does or doesn't have the heated seat buttons depending on whether you have that option.
By the way have you ever checked your cabin air filter condition?

 

I had to put myself into time out. No, really, I did. I went away for the weekend because I had to think about things, re: too harsh.

I realize I sound all uppity up there now. Sorry. However, I was trying to not get you spending money where it really looks like it's not the right course of action. On the face of it. Lil' panicky maybe... I dunno. Felt really strongly about it at the typing.

And yes, I noted your taking it to the Ford dealership and their diagnosis. I just don't understand it. Everything I know says this isn't a thing that should happen unless...

...well. Anyway. I said my reasonings earlier, I'll not rehash. For whatever that and this is worth at this point.

I do hope you find the answer. Thanks for your input on my manners, I'll try to do better. And I'm sure others would like to know what happens at the end of it, I'm very curious myself.

Good luck to you!