So, I am kinda picky about my air in cars. I hate the way the Ford operates. It's not the worst I've seen, but I'd like to improve it.

Off flow- I'd like a setting that has no fan or AC pump that simply allows natural flow while moving and I'd be willing to give up my highest fan setting if that would be possible and shift all the fan settings up one position. So, lowest fan position would be "flow"

AC pump. Why must it be on for all the positions except the chest-setting position? Here in the NW we have a lot of rain. It's nice in winter to leave the car on defrost or feet+def and just let the heat keep the glass clear. We don't need AC all the time for this and it just puts wear on the parts and takes fuel. Plus, my truck doesn't make much heat and the AC pump seems to kill even more of it in winter time when I need it to keep me warm.

That's all. Is this possible with some wiring mods?

 

I don't see why you couldn't run a simple "on/off" switch to the compressor hot wire to disable the clutch from engaging. A lot of vehicles have it but not our trucks. I'm with you on this one and I live in the Midwest.

 

I may be mistaken, but I believe the intent of having the A/C active is to condense the water vapor in the cabin air in order to dry it. That increases your perceived level of comfort.

Have to tried pulling the blower fuse to see what kind of natural flow you can acheive?

 

the A/C pump runs on the defroster setting to prevent it from seizing up over the winter... older vehicles use to not run the compressor and people were having problems with it not working come spring/summer time.. to solve this issue it was then made to run on a lower setting when the defrosters on. Think of it like a high/low setting for the compressor. itll spin to keep the compressor free but is not really building any pressure in the system.

Also if your AC compressor is running even in the non-defrost and non-a/c settings it sounds like you have an electrical issue.. It should be running in the Defrost and A/C setting ONLY!!

if your having problems getting enough heat in the winter it sound more like you have other issues in your truck.

1. Bad blend door actuator that is not closing off the outside cooler air properly. (these are prone to failure on these trucks)
2. Bad thermostat that is stuck in the open position preventing the engine from reaching operational temp. (another common prone failure)
3. Improperly rated T-stat. (you can get one thats rated for extreme high temperature climates that open early for like desert type climates. if its installed in a vehicle that experiences extremely cold winters you wont get much heat.)
4. Bad Temp sensor causing the cooling fan to run all the time.
5. Bad Vacuum Coolant Shutoff/Bypass valve. (Located on top of the passenger side valve cover. when this fails it will not supply the heater core with enough hot coolant to warm the cab)
6. plugged heater core.

I didnt see the sub model listed in your signature to know what type of controls you actually have.. but if your vehicle is equipped with the electronic climate control ford tends to limit how cold or hot the air exiting the vents can be. Where the manual controls can run hotter and colder since it is left monitored by the computer.

 

It might, but I can choose my perceived comfort levels based on my actual comfort levels in real time, rather than some engineers idea so of my comfort. It's true that AC helps deFOG (not defrost!) in extreme conditions but again, I'd rather choose that operating condition. I'd like to have the defrost work without AC because AC will dry your eyes and I find driving makes my eyes dry, worse with an heated air dryer blasting me in the face.

Great lead on the fuse I'll try that. My fear is that the positions door thing maybe connected to that circuit.

 

This may of may not be true about AC pump maintenance but, again, Id rather run it for a moment ever now and then like I do on all my other cars than have the car think for me and click and clack all the way to the parts counter.

It's true my truck has other issues. I believe my oil cooler may be plugged and is contributing to low heater box flow. I need to remove the oil cooler and bypass it as I'm no longer using it to cool oil anymore anyway so it's just laziness. But also some trucks came with a special actuator to close off one of the heat or cool or something, my truck wasn't fitted with one and it may be affecting performance.

 

Good idea, hoping for an easy way to do exactly that. But maybe something easier like clipping a wire on the other settings or something so only AC settings work the AC pump. That would help. The fan off / flow mode is also very desirable in winter.

 

if the vacuum actuator over the valve cover is missing then someone has removed it in the past for some unknown reason.. it is standard equipment regardless if the dash controls are computer based (lariat or above models were both optional and standard equipped) or mechanical (some lariat, Cabellas, and all XLT and XL models )..

also another thing i forgot to mention earlier and could be a contribution to your lacking of heat output can also come down to your coolant mix ratio too.. ntm age... the older coolant gets the less efficient it becomes in absorbing the heat from your engine and circulate it away to be cooled via the radiator or/and distributed else where as it does in the heater core.. Also too high of a coolant to water mix results in the same issue... (this is why its preferred in extreme colder climates to run a richer coolant to water mix so the engine can maintain proper operating temp).. downside to this improper mix for normal climates is it will typically cause the engine to over heat as well..

but if you were experiencing engine temps running far below norm never reaching operational temps. in addition to the other things i mentioned in my earlier post it could be someones mixed in more water than coolant... you would normally do this for extreme heat climates.. running a low antifreeze to high water mix will actually pick up more of the engine heat more efficiently to be dissipated later through the radiator..

personally i would be trying to chase your other issues first and correct them before trying to modify how it is made to work.. it certainly sounds like you have other problems that seriously need corrected to bring the efficiency back to par..

 

Well I've been through a lot of all that and I'm not trying to get more heat or ac I'm just wanting control out of both at this point.
my engine temps are good and coolant is good and filtered. Heater core is flushed and good. It's not receiving enough flow due to the oil cooler clogged I believe. It makes enough heat when the ac pump isn't working. The XL work trucks didn't always have the valve thing in pretty sure because we discussed it in another thread. The main desire at this point is to have a flow mode with nothing running essentially, no fan or ac or anything just outside air pressure flow. This is something I feel all cars should have. Alas sadly it seems to be a dying mode of operation.

 

ive had and worked on vehicles dating back well into the 70's and all of them unless the system was shut to off still ran the fan for the vents regardless of the speed setting. the only ones ive ever seen that operate in the setup you suggest were the days when you had a manually operated pop up cowl that either was either behind the hood or the sides.. like the early VW Beetles 50's era and older Model T's and such..

 

Well sparky I don't know what to tell you but maybe you've only owned American cars or haven't been paying attention but I've had many cars that operate in the manner ive suggested straight from factory from the 80's, 90' and 2000's. Even my 2012 Toyota operated in such a manner. So if you're saying that it's something that doesn't exist since the age of pop up vent cowls, well, you're wrong. "Older model Ts" lol. Aren't they all older? Anyway back to my question, to mod this HVAC to do what I want? Thanks.

 

I had a feeling this was where this conversation was going to go... just for an FYI.. ive personally owned fords, chevys, & hondas, and worked on many other makes and models over the years... new and old.. but hey what do i know. i only went to school, was certified and did it for a living for many years.. so i guess im done with this thread now.. do what you want with the vehicle..

 

Thanks? Didn't mean to insult but you were really derailing the thread and generously trying to help but weren't.

 

My '03 Lariat, no vacuum heater shutoff.

Ford and others still have A/C on/off switches in some models, and I like that option. Both of my wife's vehicles has it. Easily done with a switch or switch and relay controling the pressure switch circuit or clutch.

Defroster doesn't dehumidify the windshield very well without the A/C, which is why I believe it's coordinated.

Thinking about it, in the last 20 years I think the fan is engaged any time the HVAC is engaged in some manner in every vehicle I've been in, but didn't take a survey.

But the bottom line is that both the A/C and fan circuits could be modified so they don't engage unless you want them to. I've thought about for the F-350 on occasion.

 

Here's one.