Heater valve bypass to fix "heated dashboard vents"?

[JWA]

Originally Posted by Viva

Okay, if anyone is still with me, a question just out of curiosity (and back to issue #1, the heated vents): If the HVAC knob is in the Off position, is there still circulation through the heater core? Not that it would be practical to drive like this, but I was just wondering.

Short answer is yes, coolant still flows regardless where or how the dash mounted controls are set. For 99% of owners this isn't a problem mostly because as long as the system works to their satisfaction they simply don't care. Its not really a problem, assuming everything is working to design. Whether you/we/they/them/all y'all believe Ford's approach is good or bad it is what it is and we have to deal with it or just leave it alone. Not a problem either way but trying to change an existing design requires big money to hire it out or digging in at the DIY level.

Originally Posted by Viva

So in summary, does this sound reasonable for my rig:

1) Fabricate and install larger vacuum canister and new check valve above passenger footwell; abandon OEM canister/check valve. OR... if/since the leak seems to be small, is there something else easier I could check first?

2) Install Max Air, then install The Cold Rush which is really what I want, but you have to put in the Max Air first.

Thanks,
Viva
(massively intimidated by doing any of this!) (if anyone knows of anyone really good/trustworthy - preferably a one- or two-person shop in N or NW Arizona, please let me know).

In general if any of the DIY part of this is above your comfort level by all means don't try it. That's not necessarily trying to discourage you but to dig into something without a decent working knowledge of the system in general plus a fair degree of practical hands on experience with auto repairs your learning curve will be steep. One pit fall is disassembling things to the point the van can't be driven without a way to at least return it to driving condition.

I'd not consider adding either by hiring out or DIY this Cold Air or Max Air because I can produce 38* leaving air temps out of my A/C vents in Max Air, freeway speeds in a strictly stock configured 2000 E250. Mind you that van has all new A/C components along with fresh evacuation and refrigerant charge which makes a world of difference. (This van is front A/C only.)

Your original issue would be best solved via a work around method to finding & replacing the factory HVAC system vacuum reservoir. CarringB is spot on concerning those components downstream of it mostly because 99% of similarly described issues have been attributed to this part failing. Occasionally the vacuum line feeding the reservoir develops a leak from age etc etc but the good news there is its very easy to find and repair.

On FTE there are a number of posts relating to actual fixes for a leaking reservoir, Scotty86's link is probably one of the better ones to read.

A word of advice would be first solve the existing condition in order to restore your van's original HVAC function before doing or adding anything else. Also assure your A/C system is properly charged and working properly---this is vital. Once all this has been accomplished more than likely you'll find Ford's stock system works as well as you might need.

Keep also in mind vehicle A/C systems attempt to function in extreme conditions for which there is no real magic fix. For those who know A/C systems will atest its almost a miracle the modern day A/C systems work as well as they do.

[Viva]

JWA,

Thanks for all the detailed info. I would like to clarify something though, as it seems that I gave the idea that I wish the A/C were colder. I don't. What I wish is that I did not have to run the A/C on all the glorious days that are between 60º and 80º just to keep from roasting. It mars my pleasure in driving the vehicle enough that I am considering something different (and that is huge, as I have put a lot of time/effort/thought into this rig, and love it otherwise).

Originally Posted by JWA

Short answer is yes, coolant still flows regardless where or how the dash mounted controls are set. For 99% of owners this isn't a problem mostly because as long as the system works to their satisfaction they simply don't care. Its not really a problem, assuming everything is working to design.

But for me it is a problem. I have no complaints about the coldness of the A/C (I have front A/C only). The A/C works fine. My problem is having to use it ALL the time to keep from roasting, even if it is 60º outside. I have mostly driven with open vents in all my vehicles (unless it is really, really hot), but that option has been taken away from me in this van, and I pretty much have to use the A/C any time is over around 60º. (I don't like long trips with windows open as the wind/road noise get old.)

So the real issue I want to solve is the "heated vents" and the heat that exudes from over my knee area (above the OBDII port). I thought I understood now that these things were a by-product of a design wherein hot water is always circulating through the heater core, but in your last post I now get the impression that this isn't the case and you wouldn't recommend the products that claim to change this (?). It sounds like many other people are content to run the A/C most of the time, but I am not happy needing to do that on a cool day. I would like to either fix that or, if it cannot be fixed, I will probably go a different route for a vehicle (which would be sad, as I have put a lot of effort into getting this one the way I want it).

Originally Posted by JWA

I'd not consider adding either by hiring out or DIY this Cold Air or Max Air because I can produce 38* leaving air temps out of my A/C vents in Max Air, freeway speeds in a strictly stock configured 2000 E250.

My A/C temperature is fine, as noted above. What I want to solve is the heated vents, so I don't even have to use the A/C unless it is actually hot outside.

Originally Posted by JWA

Your original issue would be best solved via a work around method to finding & replacing the factory HVAC system vacuum reservoir. CarringB is spot on concerning those components downstream of it mostly because 99% of similarly described issues have been attributed to this part failing. Occasionally the vacuum line feeding the reservoir develops a leak from age etc etc but the good news there is its very easy to find and repair.

On FTE there are a number of posts relating to actual fixes for a leaking reservoir, Scotty86's link is probably one of the better ones to read.

Maybe I side-tracked the issue with the vacuum leak discussion? It's just that it came up in the links that were posted (which I read) and I made the vacuum/EGR connection. I probably should have started a new thread for that. I do think I have a vacuum leak, but probably only minor since it's only noticeable when pulling mountain passes or steep hills when towing), and from what I am reading, that is not causing the heated vents (right?).

Originally Posted by JWA

A word of advice would be first solve the existing condition in order to restore your van's original HVAC function before doing or adding anything else. Also assure your A/C system is properly charged and working properly---this is vital. Once all this has been accomplished more than likely you'll find Ford's stock system works as well as you might need.

I think I pretty much do have normal HVAC function, from what I have been reading. One time I had it switch to "defrost" when I was towing up a steep hill, but the rest of the time it seems to work fine/normally, except for the heated vents. Are the heated vents caused by a vacuum leak, or is this a separate topic (I will start a separate thread if so).

Originally Posted by JWA

Keep also in mind vehicle A/C systems attempt to function in extreme conditions for which there is no real magic fix. For those who know A/C systems will atest its almost a miracle the modern day A/C systems work as well as they do.

But my problem isn't in extreme conditions - actually the van is great if it is below 55º or over 80º because then I am using heat or A/C and it's like driving any other vehicle. Where it sucks is between 55º and 80º when I would normally be breezing along comfortably with vents open, but now have to run the A/C in order not to roast. THAT is what I want to fix! I want my 60º-80º pleasantly vented days back! It's really marring my enjoyment of the vehicle and driving (which I love!).

So in summary, I don't need or want colder A/C. Rather, I would like to not HAVE to run the A/C in cool weather at all! I would just like to open my vents as I have on every other vehicle I have ever owned. I thought I understood that the "heated vents" were part of Ford's design with fluid running through the heater core all the time (and that this could be fixed with Cold Rush), but now I'm confused as your most recent post sounds like I shouldn't be having this problem, and that others with properly operating HVAC systems don't have it (?) But if that's so, why did they invent Cold Rush? Again, I don't care about the Max Air, my A/C is fine --- but you have to install that first in order to put in the Cold Rush).

Thanks,
Viva

[daveb]

That is how mine seems to work. I don't know if it's a year thing but I had planned to put in the cold rush for the same reason.
The way I thought I understood it is when the system is on max the flow is shut off to the heater core and when set to any other cold mode the blend door is closed unless you adjust the heat. So on vent, even if the temp is turned to cold, the coolant flow just makes thing hotter even though the heat door is closed. Correct??? I thought the aftermarket fix was just a way to trick the system to thinking the system is set to max AC. No?

I want positive pressure on dusty roads and being I have to run the Starcool when the the Ford AC runs, it can get kinda cold when it's 65-75* out. If I roll down the windows all the dust flies in. The vent mode is just too hot while running in mild weather.

I had a vacuum leak that kept the system from switching between defrost and vent but it didn't affect the heat settings as far as I could tell.

[Viva]

Originally Posted by daveb

That is how mine seems to work. I don't know if it's a year thing but I had planned to put in the cold rush for the same reason.
The way I thought I understood it is when the system is on max the flow is shut off to the heater core and when set to any other cold mode the blend door is closed unless you adjust the heat. So on vent, even if the temp is turned to cold, the coolant flow just makes thing hotter even though the heat door is closed. Correct??? I thought the aftermarket fix was just a way to trick the system to thinking the system is set to max AC. No?

The vent mode is just too hot while running in mild weather.

Sounds like you get what I want, and have the same issue with the heated vents in nice weather (I also like to pressurize the rig on dusty roads). From what I understand, there are a few rigs (2003 or newer?) that do have the valve so they don't need the "Max Air" but can just go straight to the Cold Rush to "unheat" the vents. But apparently most (?) don't, so that is why you need to install the "Max Air' product first, and then the Cold Rush. It's not that you (we) are looking for colder air, but just that the "Max Air" is a valve, which needs to be in place for the Cold Rush to work.

Here is what I received back from the tech. department at DieselSite:

I know exactly what you mean about running in just vent - we're in Florida so it's about to be that perfect Florida winter weather soon with no humidity and the windows down.

1. The COLD RUSH will do exactly this. It allows you to use the function of the valve for any setting other than just MAX AC... for vent, ac, etc

2. Follow your heater lines up near your fire wall. If you have a valve, you won't be able to miss it - it'll be spliced right into your lines.

3. You are correct in that you would be using the 7.3L Max AC if you do not already have the valve on your vehicle.

A little worse news though is that we cannot remember just how difficult it is to install these products on the van. It's a tight squeeze for everything in there and there's definitely no change as far as how to install them but your locations may be a little different.

If you have further questions or want to talk about them a little bit more, don't hesitate to call us at the office or email back with more questions!

Thanks very much for the interest,
Dieselsite

Originally Posted by daveb

I had a vacuum leak that kept the system from switching between defrost and vent but it didn't affect the heat settings as far as I could tell.

Okay, so that is a red herring in my case, it sounds like. That makes sense to me. Especially since it seems to be a "minor leak" on my rig, and yet the heated vents are 24/7.

Viva

[daveb]

In cold weather the vent will come on warm and as the cold air flows through the ducts it will start to cool but it will usually be warmer from the outside temps. If I slow down the vent temp goes up slightly. Annoying.

[Viva]

Sounds like yours behaves *exactly* like mine does. Starting up after being parked (but engine is still warm) is even worse. There is also "generalized heat" that exudes from above my knees (over the OBDII port) - not sure if you have that too, but apparently heater core lines run there as well.

Maybe we should have an "Install MAX AC plus Cold Rush" install/get together. All those with "heated vents" who simply want to be able to use the vents comfortably between 60º and 80º are invited (plus any other forum members as well, of course!)

I can be anywhere in the SW or between there and the CA Bay Area this winter -- or maybe even PNW

[carringb]

Hmmm I don't get any heat from the knee area. At all. Even if I switch to floor heat, it really blows more onto my feat than my knees. I wonder if your doghouse it leaking air?

[daveb]

I don't either. I mean the dog house gets warm to the touch after the engine is hot but no air flow coming from other sources around the knee area. There is a bit of heat on top of the dog house that rises up to the stereo and CD's get pretty warm at times in summer.

[Viva]

Hmm, my doghouse gets really hot (but then it has a "quilted" cover, so that may hold the heat in a bit - I can feel the hot doghouse when I slip my hand under the "quilt"). The one on my 5.4 got warm, but not quite as warm as this one. I was thinking maybe the V-10 sat back a bit further (the extra two cylinders have to go somewhere....right?).

I thought I had read that the "warm area" above the knees was also part of the heater core always having hot liquid in it design -- maybe not? This is not "active" heat, such as would blow in the foot heater mode or come in the "heated" vents; it's more just a generalized warm air area. Of course without normal vents I can't get rid of it unless I run the air

On the doghouse: I'm not sure if the heat shouldn't be there, or if the heat is always there but shouldn't come into the rig (this is separate from the vents, which are still my top priority). My engine does not run particularly hot (range of 193ºF to 202ºF, but the 202 is only in very hot weather/towing/uphill). Typically it's in the 190's. So it seems I shouldn't start with any more heat than anyone else.

For the heat leaking out the top of the doghouse (which I have had on both rigs), I cut a section of black pipe insulation and wedged it in there. Looks almost stock and keeps that "line" of heat from coming out the top edge (under the radio and near the back of my cupholders). I did that on my 5.4 too - worked well on both rigs.

I mostly want to fix the vents, but am open to doghouse fixes too, as I don't need "extra" heat coming in. One thing that is frustrating is that there are so many issues/causes. I almost feel I need to install the Cold Rush just to see what goes away and what is still there to deal with. And having ambient vents would help everything, even if there was more to do later.

Ultimately, if I can't get it so that I can have fun driving again (neither roasting nor using the A/C in lovely, cool weather) then I'll have to look at other options (Sprinter van maybe). But that would be extremely irritating/depressing as I have put a lot into this van to get most things just how I want them. I really don't want to start over. I just want my derned vents!

I figure it can't just be my rig or Dieselsite would not have made two products to fix the problem (I've also read about it on various RV forums with folks who have cutaways with the V-10, although no conclusive solutions except "run the A/C." I know all vehicles have their quirks, but geez, you'd think HVAC on a 20+ year old design would not need aftermarket fixes.

I know, I sound aggravated, but I just got done with a 2,000 mile drive that should have been lovely and comfortable (ambient temps were 60's and 70's most of the way), and I had to either roast or run the AC. Bleargh.

[carringb]

The V10 does not sit further back. It actually hangs forward a little more. This way the transmission mounting and drivelines don't need to be different for the various engines (since at one point, all engines in the E350s had the same transmission, gas or diesel).

The heater core is on the passenger side, so it doesn't warm the driver side. And, I don't get warm air blowing at the passenger's knees either, but you can feel some radiant.

I have gotten hot air blowing once, only because the doghouse wasn't seated properly. I found that latching the sides before the bottom is the best way to get a good seal.