Heater valve bypass to fix "heated dashboard vents"?

[Scalf77]

If you want to use the Max AC with a controlled switch, then you need to purchase the Cold Rush also. The Max AC is just the vacuum controlled Heater/Hose control valve. (it is the part that will not let hot water to your heater core) You can use the Max AC as a stand alone item, the Cold Rush is a upgrade/add-on for the Max AC, it is a 12 volt controlled Vacuum Switch. So instead of installing the Max AC vacuum input to Port 4 of the vacuum selector switch, you install it to the output of the Cold Rush Vacuum switch. Hook the input to a vacuum source, turn the 12 volt switch on and you now have Vacuum on the output that controls the Max AC Heater/Hose control valve, you can turn off water to the heater core with the dash switch that Dieselsite provides. So the two products together will be able to do what you want.

What I was saying was for the Van, you could look at just hooking the Max AC to the Port 4 of the Vacuum Selector switch, and then you would be able to turn off water to the heater core using the Dieselsite Max Ac, this would work for three positions on the van, MAX A/C, NORM A/C and VENT. Since you really want it to work with the Vent. I have not tried that but it looks like it would work. For both trucks and vans if you hook to Port 1 (recirculation air duct door) you have a controlled vacuum source that is only on for the "Max A/C" position.

The easiest solution is to just purchase the two Dieselsite products, they come with T's, vacuum hoses, hose clamps, and pretty much everything you need for the install.

-greg

I have both products ( I have just never got around to installing them) I will probably see if I can just get away, with the Max Ac, but I won't get to it for another month at least. or i may install both, because I agree my AC works fine, I would just like to use vents when the temperature is appropriate.

[Viva]

Scalf77: Thanks for the explanation - much appreciated.

Originally Posted by Scalf77

The easiest solution is to just purchase the two Dieselsite products, they come with T's, vacuum hoses, hose clamps, and pretty much everything you need for the install.

I hear you on that. I will most likely purchase the pair and then either try to install them along with someone else (moral support, at least one vehicle not in pieces...) or have someone do it (if I can find someone I trust).

Originally Posted by Scalf77

I have both products ( I have just never got around to installing them) I will probably see if I can just get away, with the Max Ac, but I won't get to it for another month at least. or i may install both, because I agree my AC works fine, I would just like to use vents when the temperature is appropriate.

Sounds like you have the same issue/goal as I do. And you may get to it before I do, as I'm away from civilization (i.e. the ability to order things and receive them) for some weeks. When I do get to it I will report back here (and if you get a chance to do so, I would sure be interested in hearing your experience.... especially if you get to it before I do!)

Viva

[JWA]

Originally Posted by Viva

My brain is straining to remember why (or if) there was a reason that a "simple' bypass wasn't supposed to work, but I can't remember. So maybe there wasn't any reason

Viva you're not a bit dense, all this discussion with variations how your goal can be met does sound complex
mostly because you've not yet done any work with Ford's HVAC control system.

While I didn't dig too deeply into the Max Air and Cold Rush offerings I could instantly tell from their images of the kits it could be greatly simplified. My solution does what you need and in the most simple, uncomplicated and relatively inexpensive manner. Its added advantage is you'd have complete and independent control of hot coolant flow to your heater core regardless what function is set on the dashboard; Vent, Heat, Defrost, A/C or Max A/C.

As I said earlier most all vehicle systems had the heater control valve which we're going to replicate. There is no real conflict with any other power train or body system at all; think of this as we're going old skool on the heater system. The "how" is simply inserting one valve in the front heater core loop which begins at the fitting just off the thermostat housing on the front of the engine, just under the alternator.

There is no reason a single shut off valve cannot work on its own. There's no impact or interference with any power train or body system other than the HVAC portion.

Our first decision is how we're control or operate this valve; vacuum or electric only. (Keep in mind this single valve will do nothing more than stop hot coolant flow to the heater core, just one the inlet side----nothing else.) Whether we use an already present vacuum signal or just an electrical signal to open/close the valve we need an unobtrusive & easily reachable interior switch. (I've found a suitable 12 VDC valve that greatly simplifies this---it requires only installation in the heater line and a suitable switch, its here: http://www.electricsolenoidvalves.co...alves-n-o.html, the 12 VDC version.

Because that valve doesn't require integration into the vacuum system its just as simple as cutting the heater hose of choice, fitting the valve with suitable barbed hose fittings and clamp it in place. From there run one each power and ground wire and a switch to operate the valve---done.

The upside to this arrangement apart from its low cost and ease of installation is it would be independently controllable of any other HVAC function. Regardless where the Function Control is set (Heat, Vent, Defrost, A/C, Max A/C) you still have complete control of the valve. No additional vacuum hose, fittings or runs---one valve, one switch, some wire, in-line fuse holder, misc clamps cable ties etc--done.

The info we're contributing might make this seem far more complex than it is---that's due our different POV's or approaches to this. The common element is that single valve installed to interrupt hot coolant flow to the heater core, the only real differences is how we control that valve.

If you've ever successfully changed or replaced a heater hose and/or wired anything automotive your skills are in place---done. We'll talk you through this I swear!!

Sorry to yammer on and repeat myself so often.

[Viva]

It does get a bit confusing, but I think part of it is just that the basic system sounds a bit complex (or maybe mysterious until one understands how it works). But I'm always up for learning.

I have changed a radiator and hoses on my car -- just substituting stock for stock -- and have done boat plumbing work (which is always fairly ). I think the big difference on the car was very simple design (1980's model) plus all the space, glorious space!, in which to work. It's the combination of extreme "cram-edness" plus being out on the road using it currently (so it's wheels + house) that makes working on the van a bit intimidating. And there just looks to be a lot going on under there. I watched/helped the mechanic who changed the spark plugs on my '97 and holy cow, we had half the engine out, I swear!

But, it's really cool that you and others here have taken an interest (and/or have the same issue). It's more "fun" to have some group momentum on a project or problem.

[mikracer]

JWA's solution seems very simple. The end goal is to eliminate water from going into the heater core and this seems to do it with one mechanism. Turn the switch on and stop water from going into the core. You then select whatever you want on the AC system and not have to think about whether the system will work on a particular selection.

Thank you JWA for finding such a simple solution! Now who will be the first to fit this onto their van?!

[daveb]

Thanks for the link. I spent all day last week looking for a 12v valve but couldn't find one. I do want to know if it pulls power to stay closed though. For me it wouldn't matter other than using a source that shuts off unless the engine is running.

[JWA]

Originally Posted by mikracer

JWA's solution seems very simple. The end goal is to eliminate water from going into the heater core and this seems to do it with one mechanism. Turn the switch on and stop water from going into the core. You then select whatever you want on the AC system and not have to think about whether the system will work on a particular selection.

Thank you JWA for finding such a simple solution! Now who will be the first to fit this onto their van?!

I've already done this although only a few minor differences as I needed to divert coolant flow to a rear heater core.

Originally Posted by daveb

Thanks for the link. I spent all day last week looking for a 12v valve but couldn't find one. I do want to know if it pulls power to stay closed though. For me it wouldn't matter other than using a source that shuts off unless the engine is running.

Dave when I began this some 6 years ago I too searched all over hell and high water too looking for 12 VDC operated valves. Whether those in the link existed at that time isn't known but their cost is about 1/4 or what I could find back then.

We want such a valve to always be open, not requiring power to allow flow to the heater core full time. When power is applied the valve closes thereby stopping coolant and lowering temps inside the plenum. This open without power is referred to as "normally open"; "normally closed" is just the opposite, doesn't open until power is applied.

Viva you have every skill and experience needed to do my version of this mod. Get your parts together in one pile, start early in the morning and you'd be done with the actual valve installation in less than an hour, including draining the radiator first. After that the van is 100% driveable, all that remains is locating and wiring the switch.

Just for grins and giggles a Hella rocker switch with pilot light would set this install off perfectly. Since those switches require a single 3/4" diameter hole and use standard 3/16" crimp female disconnect terminals AND can be found in a blue light (= cool) this would be a nice finishing touch. Example: http://www.ebay.com/itm/12V-16A-BLUE...7e17a5&vxp=mtr

[Gooseberry]

what if you just put a better shut off valve in place of the crappy one ford uses? get one off a yota and grab the cable with the knob to adjust flow?

[JWA]

Ford doesn't use a cable-pull valve of any sort, not past '97 anyway. In fact the lack of a heater core shut off valve is why this thread was originally started.

IMHO a cable-pulled valve would be more difficult to install because running and mounting the cable inside the engine bay and cab would require a lot more work than the electric or vacuum actuated valve. The appearance would be distracting since it wouldn't fit the over all scheme or design of the interior.

[mikracer]

Can somone post a pic of the inlet hose? I'm really interested in getting the valve that JWA linked and being able to use my vent instead of AC all the time.