When I change the heater output from "defrost" to "mix" to "floor" nothing changes. I thought maybe the heater just wasn't working and posted a thread about it. Today I played with it for a little while and it seems the setting don't change. I could swear they were changing the other day but I might be wrong. What should I check? Is this a vacuum leak or some sort?
hopefully someone else will chime in on this because my mustang only blows through the defrost vents and the floor. doesnt come out of the dash vents. maybe our problems are related
Hmm, good questions, you may have vacuum leaks behind the dash, not allowing the doors to open for some settings.
Personally, I did the rotary conversion and I have no idea what "mix" does, but it sure doesn't come out the front vents. I have to turn it to "vent" to get air out the front vents.
Come to think of it, that MAY be my problem, but the hell with taking that back apart, I'll wait.
Well my problem started after I replaced my heater core but the car still gets warm and as long as the defrost works im good because there is NO WAY im going to take the dash back out again! lol Its a lot warmer ride now then before.
Sounds like a vac line...I had something similar happen a few years ago. I did have to pull the dash back though, but I left all wiring connected, as I only needed enough room to see the line..
Oh . Mine started after the heater core was replaced too! And I know what line was disconnected. For the life of me I could not find anyplace for it to go. I sure hope I don't have to pull the dash out again.
Live Fast, I'lll look at it once I'm done cleaning the yard today. I'll get pictures of the line, and maybe the two of us can figure out where it goes.
Mix means exactly what it says. It mixes the air between the defroster vents and the floor. The "vent" selection puts heat out the vents on the front of your dash, that selection is not under the "heat options" but it puts out hot air.
Ok cool, Hopefully between the 2 of us we can figure it out. I must have pulled it a loose by accident because I tried to leave alot of the vac lines hooked up. I think I might have an idea of which one it is.
Here you go.
Thanks. I think I know which tube is disconnected. Its on the passenger side. It seems pretty short. I can't figure out where it goes. I'll get a picture, but I really can't understand the schematic enough to find it. I'll get a picture.
(http://i478.photobucket.com/albums/rr148/jpc647/103_0023.jpg)
(http://i478.photobucket.com/albums/rr148/jpc647/103_0022.jpg)
The only vacuum line I can find that not plugged is this one. It goes up the dash and then loops back down and connects to the unit with all of the little outlets in the first picture. The unit thats in the bottom left corner of the glove box.
It seems this line goes out to the firewall somewhere. The manual shows that it goes behind one of the support braces, but I can't find the nipple it connects to.
Can you elaborate a little bit? lol Is the line in the picture the one you had a problem with? Where did it connect to?
Seems like a lot of you are having problems. I posted this in another thread. Luckily I had my dash apart reassembling it after painting the rusty dash frame. The vaccum actuator on the left controls the airflow between the defroster vents and the dash vents.
My Tbird is the same setup.. Check out the picture I posted. That is your culprit! With no vaccum to this actuator it defaults to airflow only to the defroster.
Another pic with dash frame removed...
What vacuum actuator? I don't see anything labeled that. I was under the impression the line needs to be plugged in somewhere above the cabin air recirculation thing.
The actuator circled on the very left... That controls the flap between defroster vents and dash vents. It's pretty far up under the dash but you should be able to see it from underneath looking up from the right of the steering column. Each actuator has it's own separate single vaccum line. The yellow line attaches to the one on the left. The black with white stripe attaches to the one for air recirculation.
Those are both connected. The black line in the glove box in my picture is what is unplugged. Its supposed to plug in somewhere near the brace for the heater box, according to the manuals. I just can't find it.
(http://i478.photobucket.com/albums/rr148/jpc647/103_00252.jpg)
The line with the arrow pointing towards it clearly is the one unpluged. And it connects back into the plug thing that the circle is around. Anyone know where these is supposed to be connected to? The dash doesn't come out too too far, and its hard to see around in there. I looked where the manual said, but I'm wondering if it connects to another side of the heater box?
I'll have a look on my car and get back to ya in a few minutes...
Thank you. I'll be anxiously waiting for your discovery.
Here it is! That vacuum connection pulled inside from the firewall. It connects to a vacuum valve under the hood on the passenger side at the cowl. You just need to fish it back through and reconnect it to the valve. The other vacuum connection on the valve goes to the vacuum canister inside the fenderwell on the passenger side behind the battery. The vacuum valve is fed by a vacuum junction on the driver's side of the firewall.
Another aspect...
Thanks for your help. I owe you a million. That has to be it. The engine "rough" idle cleared right up when I put my finger over the plug on the valve. Thanks.
Just by chance, do you know what causes the heater control to not work when the dash it apart? I was going to test it but there is no power to the unit. Just curious, no big deal if not.
Hey glad to help! I am also glad I helped you with the rough idle problem!
I am thinking since you have the dash torn out you may have no ground to anything that is installed in the dash panel. Most of the major grounds in the dash wiring connect to the metal frame of the dash, usually somewhere in the dash frame at the bottom rear inside of the radio/HVAC location, so when the dash is removed there is no ground because the frame of the dash is not in contact with the metal structure of the car.
Thanks again. I had to stop for a while, its really cold out there. I think the bolt you disconnect under the instrument cluster might have something to do with it. Either way I really appreciate the help. I owe you one. I'll finish up the reassembly tomorow, its just too dark and cold to continue. :(
wow,, i totally didnt mention the three way valve because i thought you already checked that. that little animal is the main hvac vac source. it has its own little tank in the fender well as well.
Alright. Maybe I'm mixing up vacuum canisters? In your second picture where it shows the strut tower, that vacuum line goes to which vacuum canister? I can't find it in the car. Are there two in the fenderwell? The following picture used to be in the fenderwell of the v8 car when the motor was removed. I botled it to the strut tower just because it was easier.
(http://i478.photobucket.com/albums/rr148/jpc647/103_0031.jpg)
The wire on my car that plugs into the same port of the valve enters the fender through this hole. I can't figure out where it goes from there, without taking the inner fenderwell off, which I don't want to do unless we determine something is routed wrong.
(http://i478.photobucket.com/albums/rr148/jpc647/103_0030-1.jpg)
The vacuum line (wrapped in loom) from the "vacuum canister" I posted in the first picture goes into the bottom sensor that is bolted to the back of the strut tower(pass side). As shown There is a "T" here which splits this line. One line goes to the other side of the same sensor, and the other line goes up to the firewall through a blue cicular Ford check valve, and then connects to a spout on the back of the plenum, you know the thing where is says 5.0 on it. The line which is wrapped in rubber with ribs, dead in the middle of the picture, is the line that goes to the plenum.
(http://i478.photobucket.com/albums/rr148/jpc647/103_0028.jpg)
So is this right? Where does the line entering the fender go? Its tight, I can't pull it. Is there another vacuum canister somewhere that I just don't know? Is the "vacuum canister" I bolted to the strut tower and actual vacuum canister? Is that going where it should?
the one line going into the fender well leads to a vac storage container for hvac.
if you can suck on the line and it holds your tongue to it,, the canister is ok.
that 3way valve deal sources from the vac tree,
sorage to the vac canister
uses vac at your interior controls.
The round cylinder looking one you have a pic of does the same thing but is a vac storage for a few vac opperated emissions solenoids.
They relocated the HVAC vacuum tank from down by the battery where Watchdevil's 84 has it ,to up closer to the fire wall where your 88 has it.
so the thing I relocated is not the same.
The HVAC vacuum tanks that I am familiar with are spherical or ball shaped.
The one in your pictures looks like the one they use for other vacuum controlled stuff. Like the EGR and Thermactor valves.
Okay, thats what I wanted to know. Everything is looking good, at the moment.
Here is a pic.
http://www.foxtbirdcougarforums.com/showthread.php?t=6839
So everything seems to be back together. I screwedu up te console a little bit when removing it, but whatever. The system seems to change settings fine. However when the system is on "mix" i barely feel any air coming out of the vents. But if i turn it on "vent", there seems to be some air coming out, not a lot, but some. Is this normal?
there is a flexible duct / tube that connects to the vents. you have to get to it by way of the center console being disected if i recall correctly. that flex duct is about the same diamerter as a shop vac hose but very very soft so it can kink easily.
OK would everyone go out to there TBird right now and try to ge air to come out of the vents on the front of the dash right now, please!! The mix option, mixes air between the defroster and the floor (notice how it is located in between those two settings......ever wonder why?). To get air to come out of the vents in front of your face you MUST put your selector on vent, it really is that simple. I have had 4 of these cars they are all like that, even my 76k original mile Bird is like that. I bet if you open your owners manual it will tell you the same thing.
those of us with ATC or what ever its called have a vent floor option.
That was my first impression. But after reassembly and trying it, on mix it seems more air comes out of the vents than the defrost. Thats why I asked, no need to be sarcasitc about it. Obviously there must be a leak or kinked hose somewhere...
Looking into this I can see why there is confusion here.
Cars built without A/C have both Hi/Lo and Mix positions.
On Hi/Lo the air goes to dash vents and floor.
On Mix the air goes to defrost and floor.
Cars built with A/C; 84 has just the Hi/Lo and 85 and up has just the Mix.
On these, Hi/Lo on the 84 and Mix on 85 and up, the air goes to the dash registers and the floor.
The above info is from my 84 Owners Manual and the 84,85,86 and 87 EVTMs
Sounds like you may have had some cars built without A/C
I just checked my 84 with A/C and the air goes to the dash registers and the floor in Hi/Lo.
Mix divides the air between the floor and the dash vents. So yes this is normal. On Vent all the air goes to the dash vents.
The above assumes you have factory A/C.
You know I checked the output of air coming out of my dash vents and it's not great at all!
Anyway, yes my vacuum canister is about the size of a grapefruit and it's mounted inside the fenderwell.
Okay, thats definately plugged in. I just don't understand why all of our heaters suck! I really don't. I mean should we all just weld shut out t-stats so the water gets sooo hott we have hot air? I mean I'm fed up with it and I don't know what to do.
Yes, i know the above idea is not plausible, It was a joke, sorta. lol
The heater on my 84 3.8 works great.
are both heater hoses equally hot after the engine has come up to temp? or does one remain colder than the other?
I'm a strong believer in genuine Ford thermostats. I've had problems with aftermarket ones in the past. The heat in the 85 will make you open the windows:flame:
Well I've got a question about the fan control switch? Is It normal for the connector for the fan control switch to be charred ..... I just took my dash out saturday night to replace my heater core and blower motor and when I pulled the connector loose from the fan motor switch it was completely charred.... Any help would be greatly appreciated..
It's very common. The best thing to do is replace it with a good used one. You can also remove the terminals from the connector and bend them so that they have better contact with the pins on the back of the switch. Loose contacts of course generate resistance which causes extreme heat and a possible fire.
ok thanks.. That's what I was thinking....taking the connectors out of their housing and covering them in shrink tubing so they can't touch themselves and just hooking them straight into the back of the switch.... One other thing I also seen where there were vacuum problems... Anyone know where I can get some of the small vinyl vacuum lines, Some of mine were extremely brittle, when I went under the hood to disconnect them, they just broke off...
Advance Auto Parts sells a rolled package of hard vacuum line.
cool thanks.. Let me go check it out..