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-   -   Heater valve bypass to fix "heated dashboard vents"? (https://www.sportsmobileforum.com/forums/f33/heater-valve-bypass-to-fix-heated-dashboard-vents-13588.html)

JWA 07-31-2017 03:47 AM

Quote:

Originally Posted by jblaze5779 (Post 208394)
Why couldn't I just use a manual quarter turn ball valve? I rarely ever use my heat here.

You could do that----its be far the easier way to go for this fix or mod. The only downside is when warm coolant isn't present in the heater core your windshield defrost mode may be much less effective if you'd want anything less than full cooling in that airflow stream.

I've been working on a relatively simple system were vacuum operated valves are inserted into the coolant flow, vacuum signals being independently controllable with electric switches inside the front cabin. Living in Ohio with a full 4 seasons my concoction is effective, ready year-round and very convenient too.

jblaze5779 07-31-2017 07:54 AM

I went ahead and just ordered a normally closed 12VDC actuated ball valve from amazon. It was $38. I'll just run it off a switch. If I want heat or defroster, I'll flip the switch to send power to the valve. Most times I probably wont use it. I imagine it'll decrease warm up time also during the winter.

arctictraveller 07-31-2017 12:45 PM

Does anyone know if there is a down side to completely stopping return coolant flow back to the engine? Is that coolant used to cool any part of the block or head after it departs the heater core?

jblaze5779 07-31-2017 02:23 PM

Quote:

Originally Posted by arctictraveller (Post 208620)
Does anyone know if there is a down side to completely stopping return coolant flow back to the engine? Is that coolant used to cool any part of the block or head after it departs the heater core?


I don't see how it can be. You're only blocking the coolant from circulating through the heater core. The engine should still be fine since the majority of the coolant will still be routed through it.

I thought about just putting a clamp on the line and seeing if it made any difference on my a/c before buying the valve. I need all the help I can get down here.

If you start overheating though it is good to be able to turn heat on full blast and utilize the heater core as extra cooling though so a valve is nice to have.

MadScience 07-31-2017 02:59 PM

FWIW I recently installed a bypass valve and happy with the results. This is the valve I used:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I looked at the coolant routing on the v10, and decided I didn't want to spend the time to truly understand it. So I just went with the bypass rather than something that blocks flow completely.

I attached the vacuum input to the max AC recirculation door. I may yet hack something up for the vent setting, but honestly I can also just run the AC for that case. I generally don't mind the drying effect.

Somewhat ironically this is directly related to installing the agile valved fox shocks. At 75 mph in 114 degree weather the ac vents were blowing 75 degree air while the van was much warmer than that inside. Coolant temp was at 220(+?) degrees. Slowing down helped, and before the shocks I would not have been driving that fast, but now that I can....

I've not been back out on i5 on a hot day yet, but I've seen a huge drop (10-20 degrees) in vent temperature in other situations, even fairly hot ones.

Total install time was about an hour. Edit: I needed exactly 5 feet of vacuum hose, I'd buy 7 feet if I did it over. Routing through the fender, above the fender liner and in right by the fuel cut off switch is pretty simple. Put a pan under the van, I lost about a half gallon of coolant just cutting the lines and being quick with the connections. I didn't have clamps big enough for those lines, so I did it that way. Worked fine, but the coolant is under a little bit of pressure there. Probably just from what's in the core and above it, but it gushed both ways.

arctictraveller 07-31-2017 03:09 PM

Quote:

Originally Posted by jblaze5779 (Post 208631)
I thought about just putting a clamp on the line and seeing if it made any difference on my a/c before buying the valve. I need all the help I can get down here. .

I've done just that using a pair of vicegrips with some cardboard over the hose. It definately made a difference in the temp of the air coming out of the vents, perhaps an additional 10deg's cooler. As for cutting off the entire flow , I've heard that on some engines (not neccessarily a modular Ford though) that completely blocking off the flow can cause a hot spot in either the block or the head. I don't know if this is true or not, but I didn't detect any problems when I did it, but I was hoping someone would be able to confirm one way or the other.

MadScience 08-01-2017 12:57 AM

Quote:

Originally Posted by arctictraveller (Post 208639)
I've heard that on some engines (not neccessarily a modular Ford though) that completely blocking off the flow can cause a hot spot in either the block or the head. I don't know if this is true or not, but I didn't detect any problems when I did it, but I was hoping someone would be able to confirm one way or the other.

I tried to answer that question for myself, and the best I found was this image which is for a bare chassis (class A) application of the v10:

https://www.sportsmobileforum.com/for...cture35497.jpg

I have the factory service manuals for my '99 and nothing in them is nearly as useful as that diagram.

It's helpful in that I was at least able to determine the direction of the flow from it. I don't however know what some of the manifolds are and how they function. If they are all just open areas, it's probably OK. If not, perhaps not. It was certainly easier to just install the bypass (which is plenty cheap) than to pull one of them apart and try to understand this in detail.

jblaze5779 10-10-2017 08:10 AM

I added a 12v actuated ball valve to the heater core line. Didn't really notice any colder ac temps but you can def feel the heater getting hotter and colder as you flip the switch from inside.

I think my next shot is going to be a fan on the condenser.

MadScience 02-13-2018 10:18 AM

Another update, I had a slow leak at all the connections to the valve.

I think the issue was just that my hoses were old enough to deteriorate a little from the inside. Changing the screw type hose clamps to constant pressure spring type ones didn't fix it. Neither did replacing the valve itself. Replacing the hoses did fix it.

When I installed the new hoses, I wanted to be able to just delete this mod in case it turned out to be bogus. So I figured out that I could just add some short straight hose sections as stubs to the heater core and attach the valve without cutting the pre-formed hoses at all.

So my issue was either old hose, or making the connection at a point where the hoses had a slightly different diameter. However looking at the hose, my money is on the hose deteriorating.

arctictraveller 02-13-2018 10:52 AM

Quote:

Originally Posted by MadScience (Post 221662)
Another update, I had a slow leak at all the connections to the valve..


Leaks aside, I haven't re-read the entire thread, but did you simply block the coolant flow or install a bypass? I'm still interested in knowing if there are any issues with blocking the return flow by using a simple on / off valve.

MadScience 02-13-2018 12:55 PM

Quote:

Originally Posted by arctictraveller (Post 221671)
Leaks aside, I haven't re-read the entire thread, but did you simply block the coolant flow or install a bypass? I'm still interested in knowing if there are any issues with blocking the return flow by using a simple on / off valve.

I used the Ford valve to bypass. It seemed easier than trying to think through the implications of blocking. I felt like I'd need to pull some of the manifolds off to be sure that there isn't any tricky non-obvious routing.

It's probably just paranoia, but I'm trying to get out of the business of hoping something is fine with this beast.

Edit: Draining two not entirely full gallon jugs worth of coolant from the bottom of the radiator eliminates all but a couple of drops of spillage.

JWA 02-13-2018 01:55 PM

Over this past summer I worked quite a bit with a scheme to block coolant flow from the front heater coil to achieve this "cold air vents" modification. While that didn't work out quite as expected (my fault 100%, over-designed an unnecessarily elaborate system) I did discover completely blocking coolant flow from the engine had no ill effects on any operating parameters.

As already pointed out the port from where hottest coolant flows in only a small portion of total flow so it not being "in the loop" presents no problems.

Not sure if anyone else has noticed but the 5.4 gasoline engine coolant quantity is a whopping 4 gallons. :eek: This being my first time messing with coolant I assumed the normal amount of 2 gallons would fill it up.

Its this reason Ford's have such great heaters. Even my new-to-me '05 with rear A/C & heat produces 109* F exiting air temp when the engine and all coolant have reached an operating temperature of about 175* F.

jblaze5779 02-13-2018 02:08 PM

So just to update. I put the 12v actuated ball valve on in July and haven't had one problem since. I brought a switch to the dashboard and can open it and close it on the fly. Also, I have a thermometer in my ac vent and cannot tell a measurable difference in air temp with the ball open or closed. Total project cost was about 50 bucks so I'm not really worried about it.

One plus is that when it's cold I can take the heater core out of the system to warm up. It doesn't really help that much but my 7.3 needs all the help it can get to warm itself when cold.

MadScience 02-13-2018 04:01 PM

Interesting. The difference in AC vent temperature was dramatic for me. Like 20-30 degrees less. I'm dealing with the v10 FWIW.

I wonder if your heater core might need a flush?

JWA: How do you know that there were no ill effects? It seems like fallout from a hot spot in one of the heads could take a while to result in notable damage, but once it does it might be a bigger deal.

JWA 02-13-2018 05:01 PM

Quote:

Originally Posted by MadScience (Post 221696)

JWA: How do you know that there were no ill effects? It seems like fallout from a hot spot in one of the heads could take a while to result in notable damage, but once it does it might be a bigger deal.

In what way would blocking that passage affect the heads?

While going through my experimentation I watched the dash temperature gauge as well as an OBD-II scanner programmed to report coolant temperature. Probes on the coolant lines were attached to a multi-channel electronic thermometer which obtains its readings via K-type thermocouples.

Issues regarding coolant flow problems as reported by the typical on-board sensors Ford builds into its vehicles.

MadScience 02-13-2018 07:00 PM

I'm not sure that monitoring the primary coolant flow would necessarily catch any pockets where the coolant is suddenly not moving as much as it should anymore. Such a pocket, wherever it might be, would result in an area being under-cooled.

Understanding how it's supposed to flow by looking at all the passages on the physical parts would answer that for sure. As would perhaps a better diagram than the one I've been able to find. If you have this information, folks here would appreciate it.

I feel like enough folks have been doing this mod on the 7.3 PSD that someone must have looked at this carefully by now and would have raised a point. However I'm not so sure about the gasoline engines.

FWIW, on the Ranger, which is a totally different engine, but has this valve as a stock part, Ford choose to go with the more complex to install bypass, for some reason.

jblaze5779 02-13-2018 09:37 PM

Quote:

Originally Posted by MadScience (Post 221696)
Interesting. The difference in AC vent temperature was dramatic for me. Like 20-30 degrees less. I'm dealing with the v10 FWIW.

I wonder if your heater core might need a flush?

JWA: How do you know that there were no ill effects? It seems like fallout from a hot spot in one of the heads could take a while to result in notable damage, but once it does it might be a bigger deal.


I know that's not the case since I replaced the heater core in July also. It had a nice leak going.

arctictraveller 02-13-2018 10:06 PM

Installing a shut off valve has proven to improve A/C performance for lots of us. In a fit of desperation, (it was about 105deg's in the shade and I was suffering badly) I simply clamped the hose shut and the difference in cooling was quite noticeable. As you may know, this issue is caused by the heater core being right behind the blend door, next to the plenum where the evaporator supplys cold air. If the blend door leaks even a little, hot air from the heater core mixes with cold air, raising the outlet temp. Even if the blend door doesn't leak air, eventually that plenum will heat up the whole box, again raising the outlet temp, although not as much. It might also depend on how well your A/C is working. If it's a little low on refrigerant, or the condenser or evaporator is partly blocked, cutting off heated coolant will make a bigger difference. As for a bypass valve verses a shut off valve, I have to believe Ford used a bypass valve for some reason. I had no problemsfor the short time I had it clamped off , but I can see how a reduced or eliminated coolant flow could cause a hot spot in the head somewhere. It might not become obvous for some time though, and a small area of excessive heat would probably not be picked up by any sensors unless they were quite close to the spot. Then again, perhaps it doesn't matter, but why did Ford use a bypass valve rather than a less expensive shutoff valve?

JWA 02-14-2018 04:07 AM

Anyone having any doubts or concerns that redirecting or eliminating coolant flow to the heater core on a Modular Motor as installed in the E-Series beginning model year 1997 forward should avoid the steps offered here.

MadScience 02-20-2018 11:05 PM

After replacing the hoses, I no longer have a leak on the connections to the valve, but I now I have a leak at the clamps to the replacement quick connects right by the heater core. Sigh.

I've ordered a pack of Oeticker clamps with a matched plier. I'll see if that finally does it.

I also moved the constant pressure clamps I had on those two connections just a little further away from the end of the hose, but that seems almost random at this point.

I did, somewhere in debugging all of this, flush out the heater core, and really just got a little bit of rust out. I was honestly surprised by how little came out of there. The flow seemed unrestricted, at least with a 20psi pressure regulator on the hose. Yes, I did a final flush with distilled water.

JWA: What concerns exist with redirecting? Well, other than not wanting to live through the leaks I'm dealing with? :)

Also, considering what I do for a living, which involves building highly reliable systems of a very different nature, I do appreciate the work that goes into a properly engineered product. However, we get away with so many little changes, that I really did not see this one as being as problematic as it's turned out to be.

All that said, I have regular screw type hose clamps holding together other parts of this very same coolant system without any issue. Sure, they are not the most perfect solution, but I do feel like the root cause lies somewhere other than the clamps. I'll take another shot at flushing the heater core the next time I have things apart, but really, it seemed to flow just fine.

fddjr1 01-30-2020 03:01 PM

parts for this valve
 
Quote:

Originally Posted by JWA (Post 134587)
Hey again Viva---seems we both sidetracked ourselves on your hot vent issue---my apologies for being too slow on the uptake. :a3:

To suit your desires the Cold Rush and Max Air system thing might do the trick just fine. IMHO those kits are a bit of over-kill and basically redundant, that one needs to add both in order to achieve the single goal of significantly reducing air temps when in "vent" seems unnecessary. Their configuration ends up costing at least $100 more than this same thing could be done with DIY parts, all of top quality and same function

I'm about to install something similar in that I'll have full control over the coolant flow to the heater core, able to shut it off completely independently of Ford's standard control scheme. My homemade system will consist of one vacuum-actuated valve, an electric vacuum on/off control and dash-mounted switch, all incorporated into the existing system with only those parts, nothing else required (miscellaneous wiring, tubing, hose and clamps notwithstanding. :a3:)

One link include here earlier on lead me to a search results page, hoping this takes you to the same page: https://www.thedieselstop.com/forums/...031j7148753j19. There are several helpful and informative threads there, might give you more insight into your potential cure Viva.

At any rate your situation can be remedied by stopping the hot coolant flow to the heater core---easy enough in theory. How you achieve it, weather DIY or hiring it out or enlisting the help of a trusted friend will dictate the end cost and how soon its put into action.



JWA-I appreciate your information here on the original post, wanderings, and then backto this core shut off valve. I have a 2005 E350 that was suffering fromthe dreaded bypass valve failure and was able to fix with the rerouting of thevalve and the building of a new vacuum reservoir tank inside the cab thanks to posters like you. AC no longer cuts off going uphill or when needing power, which is glorious. I'm still having AC temperature issues and mostly deal with hotclimate as opposed to cold. I'm looking at the 12v always open solenoidvalve you linked to and wanted to confirm remaining parts to get thisfunctional. I need 2x male barb end to threaded end male adapters securedto the valve, 1x automotive DC switch for inside the cabin, and some wiring topower and ground the switch to the valve (fed through the firewall/insideengine cover). Do I use Teflon tape to seal the threads of the barbedadapter to the valve? Anything else I'm missing? A few finalquestions: Any issues with this valve you can think of in the crampedspace of the van engine compartment (ie. heat)? Any non-lighted switchyou would recommend specifically (any special current handling requirements toconsider in buying the switch)? I appreciate your time and knowledge onthis 'wonderfully' designed Ford HVAC system for vans.

JWA 01-31-2020 04:50 AM

Quote:

Originally Posted by fddjr1 (Post 267279)
I'm still having AC temperature issues and mostly deal with hotclimate as opposed to cold.

Describe your A/C temperature issues for me please.

Honestly before we start adding or modifying things we'd want to know or be assured the existing factory A/C system is fully charged and operating as designed.

Its been a while since I've worked on this modification but I should have most of the information I can find for you. Feel free to PM me but we'll still update this thread in the event it might help others.

fddjr1 02-03-2020 11:36 AM

shut off valve parts list
 
Hi again JWA. Thanks for your response. So the system appears to be charged correctly with freon after we measured the pressures this weekend. The temperature at the front vent was about 45 or 46 F while it was about 77 or 78 F outside and the van was parked. It was late afternoon and the sun was setting. I'm not sure if that vent temperature is considered 'correct' or 'acceptable' and would love your take on it.

My overall issue is fighting the summer heat here in the south west and trying to maximize the cold we can get out of the system. This is why I was asking about the parts required to do the shut off valve as I had seen a few videos reporting a drop of 8-10 F at the vent just by shutting off the hot water that is flowing into the heater core.

Please let me know your thoughts.
Regards,
Frank

JWA 02-03-2020 07:27 PM

Hey Frank

I sourced an electric vacuum solenoid valve and a normally open vacuum operated coolant valve and a switch, links here:

https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

https://www.amazon.com/gp/product/B0...EGJNR9ED&psc=1

Here's photos showing where the shut off valve will be inserted:

https://i.imgur.com/P1VpFDv.jpg

https://i.imgur.com/tu6Fjim.jpg

What you'll be doing is stopping coolant from the intake crossover passage from entering the heater core. There's no detrimental effects to this so don't be concerned you'll be damaging the engine.

I'd suggest buying a replacement hose from the crossover to the heater core for this. OEM direct replacement would be great since it will already have the Quick Connect fitting installed. The alternative is to buy the pre-formed hose without QC fittings and use Dorman parts instead.

Keep in mind the OEM hose has a restrictor fitted whose function I don't know but if the factory saw fit ti install it perhaps its good to follow suit. Any replacement hose won't have that already installed so you'll transfer the one from the existing hose to the replacement.

The idea on this set-up is when the vacuum solenoid is not engaged coolant flows as it would normally. Should defrost be needed you'd have heat to the air stream which is usually necessary.

If you engage the vacuum solenoid coolant to the heater core would be stopped and theoretically reduce temps inside the evaporator case resulting in "cooler" air through the vents.

For a vacuum source I'd tap into the existing vacuum system for the ducts---naturally you'll need a fused 12VDC source for the vacuum solenoid. I'm not exactly sure how much amperage that pulls so tapping into an existing under-dash circuit would be okay as long as you don't over load the tapped circuit. Perhaps the power port or cigar lighter would work IF you don't exceed the 20 amps each is rated to carry.

So that's the quick view and parts list---I hope this helps. I'd be willing to share my phone number if you'd like to consult during your process--always glad to help if I can.

fddjr1 02-04-2020 10:55 AM

Hi JWA. Thanks for the detailed reply and pictures and also the offer to chat with me directly if need be. I think that all of this is totally helpful. I just had a few follow on points that I wanted to mention after going through the whole thread:

1) your suggested parts would be a cheaper alternative to the max cold setup where they made you buy both the vacuum actuator valve and the switch to fire the valve? Am I seeing that correctly?

2) Midway through this thread you mentioned a purely electric solenoid valve at this site: https://www.electricsolenoidvalves.co...alves-n-o.html. They are still for sale so I was wondering if you had finally ever used them in your setup? They are $60 without the barbed fittings so probably another $10 for those and would be double what your setup using the vacuum based valve but still 1/2 the cost of the max cold setup at like $120. It seems to me that this is a more elegant setup (if the valve holds up to the heat) since all you have to do is wire in a switch.

3) In your explanation of the OEM hose, I wanted to make sure I'm clear. Earlier in the thread, you mentioned to one of the posters that this hose was one piece in the OEM world but that due to the removal of the rear heater or some other aspect, the hose was split and this plastic fitting was put in the middle. Just to clarify, does the OEM hose from Ford come as one piece from the cross over to the core or is it sold in two segments with the hose coupler in your picture?

With respect to 1) above, your parts gets you a switch activated setup still associated with a vacuum valve similar to the setup on the max cold (or whatever it's called), but somewhere in the original thread, one of the posters described the color coding for the back of the control panel that allowed you to tap into the factory panel to activate the vacuum on the vent, ac, and max ac settings, which in theory would remove the need for the switch, but would force you to mess with the panel (if you're comfortable doing that).

I'm leaning towards 2) with the solenoid valve as a one part solution (plus a switch). I chatted with the vendor and they indicated that the valve's minimum running temp is 170 deg f as that is what temp the solenoid gets up to internally and they didn't see an issue with using in the car application. So assuming it's fine, I would get that valve, 2 male barb fittings, and the switch you suggested and install them in the spot you indicated in your pictures. Does that make sense?

AGAIN, many thanks for your time responding to my questions. I'm continuing the thread just to have all the info posted so others may see. And I can report back after with pictures on what I did, so future van folks can benefit from our journey!!

JWA 02-04-2020 12:48 PM

Quote:

Originally Posted by fddjr1 (Post 267513)
Hi JWA. Thanks for the detailed reply and pictures and also the offer to chat with me directly if need be. I think that all of this is totally helpful. I just had a few follow on points that I wanted to mention after going through the whole thread:

1) your suggested parts would be a cheaper alternative to the max cold setup...

I'm not familiar with that set up so can't say

Quote:

Originally Posted by fddjr1 (Post 267513)
2) Midway through this thread you mentioned a purely electric solenoid valve..... It seems to me that this is a more elegant setup (if the valve holds up to the heat) since all you have to do is wire in a switch.

This would be your choice but I didn't go forward with the electric valves for two reasons: 1) Wasn't sure it would hold up over time in an automotive-type setting regardless what the vendor claims. 2) Vacuum operation was my preference because the opening and closing is accomplished more slowly than the snap-open solenoid valve. Yes it does add a component which I never saw as a downside. Again personal preference, no real right or wrong way here. :)

Quote:

Originally Posted by fddjr1 (Post 267513)
3) Just to clarify, does the OEM hose from Ford come as one piece from the cross over to the core or is it sold in two segments with the hose coupler in your picture?

I added the coupling to a hose I'd previously used with the shut off valves I show. Rather than replace the entire hose joining them together seemed like a good idea. Plus I wasn't sure if I'd re-install a valve in the place so the coupling left that option open.

The OEM or aftermarket replacement hose would come in one continuous part.

Quote:

Originally Posted by fddjr1 (Post 267513)
With respect to 1) above, your parts gets you a switch activated setup still associated with a vacuum valve similar to the setup on the max cold (or whatever it's called), but somewhere in the original thread, one of the posters described the color coding for the back of the control panel that allowed you to tap into the factory panel to activate the vacuum on the vent, ac, and max ac settings, which in theory would remove the need for the switch, but would force you to mess with the panel (if you're comfortable doing that).

My method gives full and independent control over the shut-off function regardless where the Function Control Switch is set. I like that scheme but again this might just be personal preference.

Quote:

Originally Posted by fddjr1 (Post 267513)
I'm leaning towards 2) with the solenoid valve as a one part solution (plus a switch).

Quote:

Originally Posted by fddjr1 (Post 267513)
AGAIN, many thanks for your time responding to my questions. I'm continuing the thread just to have all the info posted so others may see. And I can report back after with pictures on what I did, so future van folks can benefit from our journey!!

Glad to help any way I can. Once you have your solution up and working please post back with your choices and how well its working. :d5:

coloradoup 02-18-2020 05:54 AM

Jwa
 
JWA, is there any reason why your latest parts list wouldn't work on my 2001 E 350 7.3 van? I have the rear heat and AC on my van. Not sure where to hook into the vacuum line.

JWA 02-18-2020 05:46 PM

Quote:

Originally Posted by coloradoup (Post 268236)
JWA, is there any reason why your latest parts list wouldn't work on my 2001 E 350 7.3 van? I have the rear heat and AC on my van. Not sure where to hook into the vacuum line.

If you're referring to the parts I list in post #104 then no there's not a single reason they'd not work in your year van. I dare say they'd work in any E-Series from at least 1997 until end of life in 2013. I'm not familiar with the 2014 and later cutaway cab/chassis heating systems I'm sure those would work there too.

I don't know where the diesel vans obtain their vacuum signal but easiest place to find and tap into that source is under the inspection place located middle of the dash board, looking like this:

https://i.imgur.com/WigQF6U.jpg

I'll recommend you view this post I created over on FTE in the Van's tech folder----should be helpful in gaining a better idea of the stock HVAC system and its operation as well as various components. Here's a link: https://www.ford-trucks.com/forums/1...-controls.html

Once you've viewed that feel free to ask any question you have remaining how to utilize my info and suggested parts in your own van.

coloradoup 02-18-2020 07:22 PM

Post # 104
 
JWA,

Yes that was what I was referring to. Thanks for the response and I will check out your link.

Adventure Driven 05-02-2020 11:06 AM

where is this port located that I can get vacuum from ?


Quote:

Originally Posted by Scalf77 (Post 134797)
The Cold Rush is just an electric vacuum on/off control and dash-mounted switch, hook it to a always on Vacuum source and you now have control with a switch. The Mac AC Assist is the vacuum controlled heater core shutoff valve, you can use the Max AC assist by itself, to turn off the flow to the heater core by hooking to Port 1 (White, Recirculating air duct door) , this has vacuum when the switch is in the MAX A/C and Off positions. Adding the Cold Rush lets you instead control it with a switch.

Looking at diagrams for the Van Function Selector Switch (2004, V10) is appears to me that I could hook the MAX AC to Port 4 (Blue, Floor Panel) This has Vacuum in the Max AC, Norm AC, and Vent positions. The heater core would still be active when the switch was Off, Floor, Mix and Defrost .

I believe trucks use Port 6 and not Port 4, this has vacuum when in the extra switch setting Floor/Panel, that the van does not have. It would be very probable that you would want the heater core working in this position so that does not give you an option other then Max A/C position, or by adding the vacuum control switch "Cold Rush"

-greg


VOODOO7.3 07-18-2020 11:16 PM

Viva,
I read your original question. I did not read the next 10 pages of replies though. Before you pull everything apart, might want to check that the blend door (directly above where front passengerís feet hit firewall). That flapper door sometimes gets blocked by leaves or debris. Next, you might want to check out my post in this related thread covering vacuum hoses and reservoir.
https://www.sportsmobileforum.com/fo...nts-17921.html
In your case, with gas engine, you need the vacuum reservoir and related hoses all intact and airtight. The hoses may have cracked near connections to vacuum reservoir. It is important to note that with a gas engine, you cannot delete the vacuum reservoir like you can on a diesel. It holds some vacuum between trips. Easiest way to reconnect new hoses (if necessary) is to cut an access hole (at 12:00 above front right tire at top of inner fender). The reservoir on all Ford vans is between inner fender and fender. If that is necessary, make a coverplate for hole and add your favorite undercoating afterward. Hope this helps. Cheers!

JWA 07-19-2020 07:07 AM

Quote:

Originally Posted by VOODOO7.3 (Post 277361)
Viva,
I read your original question. I did not read the next 10 pages of replies though. Before you pull everything apart........


Quite unfortunate you didn't read the numerous replies because for the most part this issue has been asked, answered and solved in a way. UNTIL or UNLESS one removes hot coolant from the heater core--where its present 100% of the time--we'll have "heated" vents. The numerous fixes proposed and implemented to good effect shows its NOT necessarily related to the blend door, neither mechanically or electric controls.

Your suggestions would work IF something were amiss in the control portion of the HVAC system---we determined earlier on that wasn't the case here. Additionally this issue was originally presented for solution way back in 2014!


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