HVAC goes to floor/defrost while accelerating/cruising on Expressway

[His Royal Ghostliness]

Two completely different things, friend. Auto temp is auto temp, all it does is fuck with the blend door and fan speed in an attempt to maintain the temperature you desire no matter what's going on outside - which vent it blows the air out is still your choice. All the TBL does is prevent a dumbass driver from freezing their feet by running the HVAC setting on floor while engine is still cold. I suppose it adds to the convenience factor in that said dumb shit can set the temp to 90F and not have a reason to whine like a little bitch the air blowing on their tootsies is ice-cold for the first 5 minutes of the engine running. Funny thing if the system is set to defrost mode (and this is most likely where it will be set in the winter time by the mirror-fogger to prevent them from, well, fogging the mirror), the TBL won't stop it from blowing said ice cold air full blast at the windshield. Or out the panel vents, for that matter. So the lil whiny bitch still has all the reasons to bitch and whine that their fingers are getting frozen to the steering wheel or their breath is icing up the inside of the windshield to the point they can't see shit thru it, but God forbid they have to suffer thru the medieval-torture-level event that is cold air on their feet... Like I said, stupid solution for a problem that was really never there to begin with - IMHO if the dumb shit behind the wheel needs a half-assed "nanny" feature to keep them slightly less uncomfortable while car is warming up, they probably shouldn't actually drive anywhere during that time. Which, if you think about it, is a good practice regardless of what the vehicle is - cold shit wears faster than warmed up shit, let your shit warm up a bit and it won't wear out as fast, bonus points for the loose nut behind the wheel not having to first wear 15 layers of clothes and then shortly thereafter pull over to remove good 10 of said layers.

For the record I owned a TBL-deleted Panther with auto-temp that still worked just fine. One does not really prevent the other from doing its thing.

[tjc78]

+1 on TBL and +1 on getting it out of there altogether. The Auto Temp will continue to work just fine except like was already mentioned floor will blow even when the engine is ice cold. I disabled it in both of my boxes.

FWIW every new car I've driven with Auto Temp prevents the system blowing cold air to floor until the engine is warmed up. I fight with my wife every morning because she cranks her side up to 85 in the Enclave hoping for warm air. I explain she ain't getting shit until the engine warms up.

[His Royal Ghostliness]

I go outside, awaken the beast, crank the HVAC up, then go back indoors. 5 minutes later weather conditions are much more manageable inside the human habitation compartment, another 5 minutes and I'm all set for the T-shirt and flip-flops. Finding something to occupy myself with for 5-10 minutes really isn't hard. And if I could run remote start I'd be downright abusing the hell outta that thing

[DerekTheGreat]

LoL ghosty, you guys are hilarious.
Yes, TBL is worthless as HVAC works in any other position at any temp setting. Furthermore, when windows are frosty it has been my experience that despite your temp setting, you need to have the blower on high.
Anyway, I know the TBL is junk but the thing had it from the factory and I just replaced with with a pricy Motorcraft unit. Initially I rebuilt one but that didn't last long..
I think you guys are right about it though, I tested vent position and it also started to drift up to defrost if I was accelerating hard. Going to plug the vacuum lines going to the TBL to see what happens. After that I'm going to investigate soup can and check valve. I've given the book a look through and from what I'm seeing I think my problem is one of those three as the cruise control still works at 80mph+. Can't figure out how to read the vacuum schematic from the book though, so confusing to figure out what position they're talking about and from the TBL's routing diagram I'm not seeing why that even matters.. I'll try to post a pic of it to see if someone else can decipher it..

Sent with my phonic while eating biscuits & mustard with French-fried taters mm-hmm.

[DerekTheGreat]

Page courtesy of Ashley's foot

Sent with my phonic while eating biscuits & mustard with French-fried taters mm-hmm.

[jaywish]

Yup I like my tootsies kept warm, wah wah wah, I don't want ice air blown on my footsies.

[gadget73]

The one connection on the TBL tees straight off the source vacuum supply. Trace out the black line and you'll see it. If that leaks, its the same as a leak at the can.

[DerekTheGreat]

True, it does indeed and if it leaks I could see that being a problem. However, looking at the schematic and assuming it doesn't leak I'm left puzzled as to why they routed vacuum to the TBL, looks like one big loop that when closed or open it shouldn't make a difference yet with the old part I could tell when the car was hot; you'd feel the floor vent open up. Guess with a loop in the system it won't pull vacuum on the motors? Or is there something I'm missing?

Sent with my phonic while eating biscuits & mustard with French-fried taters mm-hmm.

[gadget73]

It forces the fresh air / recirc door to close so you don't get air bleeding through in the floor position just from air being pushed through the intake vent. It shuts that off when the engine warms up so the door ends up moving back to fresh air.

[His Royal Ghostliness]

Yup I like my tootsies kept warm, wah wah wah, I don't want ice air blown on my footsies.

Just warm? You're a wimp, I crank my temp up to 11 and then drive in flip-flops thru blizzards and stuff. It's quite nice if your engine likes to run at 200-220, lousy heat is something I never had issues with - yup that thermostat is going right back into the engine, I know how it works and I like how it works so I ain't messing with a new one that may or may not operate the same way.

By the way I don't dislike the overall idea of the TBL setup, I dislike the fact they limited it to floor setting only. Cause, you know, some of us like warm air on our fingers too while gripping the steering wheel for dear life No, seriously, I've found that in winter conditions chances are I have adequate footwear to not care what the floor setting on the HVAC does (at least for a while), but having less-icy air being blown on my hands while operating the steering wheel would be nice. Kinda one of the reasons why I like to let vehicles warm up, the warm breeze on the fingertips is simply godsend My truck has manual recirculation door override to simulate an all-position TBL function. '87 and early '88 trucks actually had that setup from the factory, earlier and later models were your standard setup tied into the A/C stuff tho.

[DerekTheGreat]

I like using the panel for heat but it dries my baby soft skin out too much. I like using the floor position instead. Actually, I like to use the floor and defrost position but with these Fords it kicks the A/C compressor on and me not like that so much. If I wanted to defrost, I'd select defrost

Sent with my phonic while eating biscuits & mustard with French-fried taters mm-hmm.

[gadget73]

Wimpy heat is one reason I went back to a stock thermostat from the 180 I had at one point. 15 degrees makes a big difference. The truck has really good heat too, I had it on defrost to keep the windshield clear and it was hot enough that I had to crack the window to keep from dying in there.

[sly]

+1 stock thermostat. Even with my huge radiators, it still runs at 195-200 until I'm towing stuff in the summer with the AC on... then it creeps up to 215. Meh.

[gadget73]

honestly if the radiator/fan isn't sufficient to keep things cool with a stock thermostat, a colder one isn't a magic pill either. It will just take a little longer to overheat.

[sly]

pretty much. Which is why when I started asking more of my cars, I upgraded the cooling. Stock cooling was fine until I started towing stuff.