Heater control valve

Post by **HenryJ** » Wed Mar 26, 2003 9:00 pm

I just came across my next mod!

Water is circulated through the heater core at all times. This is why it is so hot during the summer even when the heat is turned off.

I'm going to add a control valve:

Balkamp Heater valve part# BK 6601414 cost $18.99

It can be operated with a cable. I plan to just close it manually from under the hood for now.

I may use a vacuum controlled valve so that it will operate automatically with the stock controls eventually.

Edit: Changed my mind on the valve to use, and edited the above info.

I will be using this until I get time to figure out how to install the vacuum operated valve.

a2b · Post by **a2b** » Wed Mar 26, 2003 11:00 pm

alright, this is something that i am going to do for sure!

cuz even when i dont want to run the a/c and just have the windows down. i do any ways so the hot air wont burn my toes off

Jim · Post by **Jim** » Thu Mar 27, 2003 6:49 am

Be sure to report on how this works. I can't believe there isn't one in from factory. Just be sure that shutting off the circulation to the heater core doesn't eliminate cooling flow to some part of the engine

Otherwise 2 valves & 2 "T" connections would be needed to divert the flow.

Post by **HenryJ** » Thu Mar 27, 2003 8:28 pm

I will keep you all informed how it works! I'll do the install this weekend. The weather won't be warm enough to close it for a month or so though.

It won't affect the engine circulation of coolant. There are a few things it could do that would be bad news.

#1-By shutting off the flow there is the potential for air to be trapped in the heater core. This is a real problem for someone running Dexcool which is very sensitive and prone to air causing contamination. That withstanding, any air pockets have the potential for oxidation.

#2- Waterpump cavatation. The pump we have has been re-designed to solve the Dexcool cavatation problems that occured with the first pumps. But by shutting off the flow to the heater will I be creating a new cavatation problem? I may never know , but since the green is less prone to cavatation I won't worry about that too much.

#3- The air conditioning system MAY use the heater core to help dry the air inside the HVAC system, therefore I may see an increase of moisture inside the system. Moisture + metal = rust (oxidation).

#4- the heater core though small does offer some additional cooling. There is the potential for an increase in operating temps. I have installed the larger radiator, so that is a non-issue for me.

None of these are things that will be noticeable for anything less than long term longevity.

I guess I'll just be happy if I can have cool feet and a cooler cab.

I really do want to use the vacuum operated valve for the system (BK 660-1200) , but haven't had time to tear into the vacuum control system to find the best place to tee in. It is not just a simple decision since the temp control door actuator has three positions. This will require the valve to be open for two of the positions.

I am also unsure as to whether the valve should be normally open or closed. It may be easier to use a vacuum solenoid, something like the EGR uses on the first gen. S-10 to activate the heater valve via a switch.

So many different ways to solve the problem, it will just take some time to find the most complicated way to make a simple mod

P.S. the first cable operated valve that I posted has been replaced by a plastic version. That is one reason I changed my mind and decided to use the one posted above for now.

quickbiker · Post by **quickbiker** » Fri Mar 28, 2003 7:19 pm

Wow, unbelievable. I'm gonna have to go looky now. Sounds like a great mod.

Post by **HenryJ** » Sat Mar 29, 2003 11:33 am

Installed the mechanical valve.

It is in the open position, since it is still freezing nights here.

That was a mistake! The valve was a leaking mess. Read on to see the better way to do this-HJ

quickbiker · Post by **quickbiker** » Sat Mar 29, 2003 1:45 pm

Did you install it in the oulet or inlet to the engine? I would assume the outlet from the engine?

Post by **HenryJ** » Sat Mar 29, 2003 2:01 pm

quickbiker wrote:Did you install it in the oulet or inlet to the engine? I would assume the outlet from the engine?

Yes

It is in the hose that flows to supply the heater core, however it should make no difference since, it is just there to stop the flow not completely isolate.

There will still be some heat transfer by conduction. With the flow stopped it should be minimal (I hope).

Either line should work to stop the flow , It just happened that the heater inlet line was the easiest to install the valve.

I mounted it just behind the double hose bracket over the right hand valve cover. I figured that it would be well supported there.

Anything has to be an improvement. I can't believe the steps backwards they have taken in the HVAC systems. Most manufactuers used a control valve, even in the late eighties.

Seems like it is a conspiracy! You have to use the AC to keep cool , there by using more gas! One more thing I can blame on the oil companies

quickbiker · Post by **quickbiker** » Sat Mar 29, 2003 2:29 pm

Same thing with the A/C running when defrost is on. I have always disconnected my compressor in the winter/fall/spring months. Saves allot on gas when defroster is used.

Post by **HenryJ** » Sat Mar 29, 2003 2:35 pm

Another mod? AC compressor cut out.

I used to do the same thing and removed the belt on my old S-10 for the winter months.

Rusty · Post by **Rusty** » Sat Mar 29, 2003 2:45 pm

I have a friend of mine that specializes in auto A/C systems. I was going to do the same thing with a cutout switch on my truck for the winter months but he told me something about you have to run these newer design systems often to keep the seals oiled in the compressor, otherwise they dry out and go bad. I don't totally understand what he was talking about but I've left mine alone.

Jim · Post by **Jim** » Sat Mar 29, 2003 2:53 pm

How about this setup:

A vacuum heat control valve:

And a Corvette Headlight Door Override Valve:

Rusty · Post by **Rusty** » Sat Mar 29, 2003 3:04 pm

That would work. I once did a similar setup but used an electric vacuum valve (from some early 80's nissan - I don't know what it did) that I rigged with a toggle switch. The only thing I did wrong was the heater valve opened when it had vacuum and I hooked the source directly to the manifold. Go up a long hill in the winter and all of a sudden my heater was blowing cold air!

Post by **HenryJ** » Sat Mar 29, 2003 3:21 pm

GaryH wrote:I have a friend of mine that specializes in auto A/C systems. I was going to do the same thing with a cutout switch on my truck for the winter months but he told me something about you have to run these newer design systems often to keep the seals oiled in the compressor, otherwise they dry out and go bad. I don't totally understand what he was talking about but I've left mine alone.

Sounds very reasonable to me. It is best to run the system ocasionally to keep the contaminants from collecting and plugging the condensor. The newer systems use such small passages they don't recommend flushing them during a repair, just replace the condensor. Yet another step backwards

Post by **HenryJ** » Sat Mar 29, 2003 3:30 pm

Jim wrote:How about this setup:

A vacuum heat control valve:

And a $$Corvette$$ Headlight Door Override Valve:

That looks like it would work great too. Only one problem the dollar signs in the GM dealers eyes

There is a Chrysler/GM valve available for $15-

It would be nice to tee into the mode actuator circuit to operate it. That way it would function normally with the stock controls.

If that is a hassle or not very practical, there are a number of vacuum control solenoids available, ie. mid '90 Ford uses them fo engage the front axle, GM uses them for the same , Mid '80-early '90's Chrysler, GM use them for the EGR sysems. It would just be a matter of finding the availability and price to make a decision.

With a solenoid a switch could be use to open or close the vacuum.

Rusty · Post by **Rusty** » Sat Mar 29, 2003 3:55 pm

"Vacuum control solenoid". That's what I was looking for! I called it a "electric vacuum valve". And to think I actually used to be a mechanic years ago!

Post by **HenryJ** » Sat Mar 29, 2003 4:27 pm

GaryH wrote: Go up a long hill in the winter and all of a sudden my heater was blowing cold air!

They solved that with the installation of the vacuum acumulators. Ours is the box in the upper left rear portion of the front fender.

You do raise a good point though, and another reason it would be best to tie into the existing controls

Rusty · Post by **Rusty** » Sat Mar 29, 2003 4:41 pm

HenryJ wrote:
GaryH wrote: Go up a long hill in the winter and all of a sudden my heater was blowing cold air!
They solved that with the installation of the vacuum acumulators. Ours is the box in the upper left rear portion of the front fender.

You do raise a good point though, and another reason it would be best to tie into the existing controls

Actually, I brought up that part more for the amusement factor although I don't think that Jeep had a vacuum canister anywhere. I had an old '53 Willy's Jeep that had vacuum powered windshield wipers. Their antics weren't so amusing.

Post by **HenryJ** » Sat Mar 29, 2003 5:03 pm

GaryH wrote:I had an old '53 Willy's Jeep that had vacuum powered windshield wipers. Their antics weren't so amusing.

I know exactly , of what you speak!

My old '56 Studebaker pick-up. During a pouring down rain storm, getting ready to pass a slow poke on the road... nail the throttle to pass ...the wipers stop!

...more fun times

Jim · Post by **Jim** » Sat Mar 29, 2003 5:31 pm

HenryJ wrote:
GaryH wrote:I had an old '53 Willy's Jeep that had vacuum powered windshield wipers. Their antics weren't so amusing.
I know exactly , of what you speak! My old '56 Studebaker pick-up. During a pouring down rain storm, getting ready to pass a slow poke on the road... nail the throttle to pass ...the wipers stop! ...more fun times

I had totally forgot about that vacuum wiper pause under acceleration thing, my first car had that...57 Chevy

Rusty · Post by **Rusty** » Sat Mar 29, 2003 5:38 pm

Jim wrote:
HenryJ wrote:
GaryH wrote:I had an old '53 Willy's Jeep that had vacuum powered windshield wipers. Their antics weren't so amusing.
I know exactly , of what you speak! My old '56 Studebaker pick-up. During a pouring down rain storm, getting ready to pass a slow poke on the road... nail the throttle to pass ...the wipers stop! ...more fun times
I had totally forgot about that vacuum wiper pause under acceleration thing, my first car had that...57 Chevy

It was really ugly with the Jeep. Come to think of it, the Jeep was really ugly. What I had was a "Utility Wagon", not a CJ. It had an "F-Head" 4 banger in it. Very underpowered (but with 5.38 gears and low range 4wd, it would almost climb a tree). Anyway, you pretty much drove it floored all the time which meant that the wipers didn't work at all unless you backed off the throttle for a second. It was like permanent intermittent mode.

Brad · Post by **Brad** » Sun Mar 30, 2003 7:16 pm

How about the A/C cut out for steep hills and towing in the summer? Anybody ever heart of one?

Brad

Post by **HenryJ** » Thu Apr 24, 2003 5:46 pm

Don't waste your money on the first valve that I installed! It leaked and no amount of tightening the thread packing helped the situation.

It did noticeably reduce the amount of heat in the interior. This was the first time I had cool feet since I've owned this truck.

I guess it was the push I needed to install the vacuum operated valve.

I returned the "screwy" valve for credit and got this one-

$3 cheaper too

Ok, here's what I did to operate it with the stock controls.

Behind the glove box there is a bundle of vacuum lines. I cut the red one and inserted an inline tee fitting using small pieces of rubber vac. hose to attach it. then used hard plastic vac. line inserted through the antenna grommet into the engine compartment , up to the new control valve, again attached with a small piece of rubber vac. line.

This turns off the heat in all positions except the two defroster selections (last two at full clockwise), regardless of the temp control setting.

It would have been nice to control it using the temp selector, but it is electrically operated.

This was the simplest way I could find.

My plan is to just open the glovebox , disconnect the tee and cap it in the wintertime. For spring , summer and fall weather this should work well

There really is a big difference in the circulation air temp., even with the fan off now.

Jim · Post by **Jim** » Fri Apr 25, 2003 7:34 am

HenryJ wrote:It would have been nice to control it using the temp selector, but it is electrically operated.

This was the simplest way I could find.

If you can find a place where the flapper door can contact one of these. That may work

Thanks, another good option!

I did lots of digging under the tight under dash places, space is something there is not much of.

I was not able to find a workable solution to using the temp selector, since it uses a variable voltage to position the doors.

I suppose there could be a way to do it, but simplicity was a part of my decision to go this route.-HJ

Post by **HenryJ** » Fri Apr 25, 2003 2:57 pm

I updated my personal webpage (ThunderII ) and added a Mod page for the Heater control valve

24digger · Post by **24digger** » Fri Apr 25, 2003 8:38 pm

where did you buy the valve?

Post by **HenryJ** » Fri Apr 25, 2003 8:51 pm

I bought it at my local NAPA, there is a link with the part # on the mod page. It is available online:

NAPA online Heater valve part # 660-1200

24digger · Post by **24digger** » Fri Apr 25, 2003 9:09 pm

thanks, I'll check into it. looks like a great mod. I also have a lot of heat inside the cab.

Post by **HenryJ** » Sat Apr 26, 2003 6:25 am

Turn your heater off on a warm day and feel the air blowing down by your right leg.

It can be pretty miserable even when the outside temperature is only in the mid-seventies.

Now there is cool air being circulated!

The only draw back is that if you need some heat , the AC will be kicking on in the defrost positions. That is why I plan to cap the tee for wintertime.

FYI- to get behind the glove box, take a finger and raise the metal "loop" stop in the left upper back of the glove box.

Post by **HenryJ** » Sun Apr 27, 2003 5:40 pm

Tested on today's geocaching run. One word!-

Koolfeet!

Post by **HenryJ** » Sat Mar 15, 2008 4:49 pm

Made an addition to the heater control valve today. I added an electric vacuum control valve. Now I have a switch on the dash below the HVAC controls for my temperature control valve. Push the switch and coolant flow through the heater core stops.

F9K9 · Post by **F9K9** » Mon Mar 24, 2008 9:14 pm

Holy resurrection, Batman!

roadrunner · Post by **roadrunner** » Mon Mar 24, 2008 9:18 pm

Next thing ya know Brule will have that rocket-ejector seat too! (If he doesn't already)

Mcfly Minis · Post by **Mcfly Minis** » Sat Nov 19, 2011 7:50 am

Woah, woah Woah. You guys are attacking this problem all wrong. There is a simple fix to keep the heat off your feet.

Here is the how to, copied from another forum:

There's a hot feet fix! I copied this from one of these forums. I did this to my truck a few years ago and it works perfectly, just as stated.

Found this on GM's techlink forum:

quote: If you can find vacuum schematics a few years back you will see that they added a vacuum actuator to the case called a "slave" valve, it has a grey hose going to it from the control head.

BUT this is only supposed to exist with AUTO CLIMATE CONTROL!

A bad example is doc# 389165, it shows the hose and actuator I speak of but I can't find anything that shows operation for the "slave" door.

What happens on vehicles with C60 manual HVAC is that the door causes ambient air under pressure at the cowl to be forced through the heater core making it nice and toasty and cooking the driver's foot because the mode door rests in the "heat" position.

Open the glove box, lift up the wire hook and swing the door down. Now you will see right in front of you this actuator with the grey hose, take the grey hose off the vacuum actuator and stick a bolt in the end of it so it won't hiss or leak, tie it back so it won't rattle around and close the glove box.

You just fixed this concern, made the customer happy, flabbergasted your SM and if you think I am full of dookie, try all the other modes. They are TOTALLY unaffected by disconnecting that actuator, the heat is just as hot and the A/C is just as cold.

I think in the '96 manual comparing the vacuum scematics on C60 and whatever auto is on the utility you will see that the grey hose and the actuator are not supposed to exist on C60 manual HVAC vehicles.

I am not exactly sure what this "slave" door is supposed to do but I know when you turn the HVAC knob to Off it fries your feet.

I think someone sold them on the idea they could use one case for all units and neglected to mention that you'd have a few hundred thousand folks with burnt toes.

I thought TAC figured this out by now with someone's help I guess I never called and told them because I know how to fix it already.

I have done this to half a dozen customer's cars and they all leave happy as a lark. Call me nuts if you want but that's how to fix it and althought it is "normal" (because ALL of them do it) it's still wrong.

Mcfly Minis · Post by **Mcfly Minis** » Sat Nov 19, 2011 7:55 am

here is a picture of said grey vacuum line

Post by **HenryJ** » Sat Nov 19, 2011 8:55 am

Thanks for the bump. Hot Feet Fix

It is very likely that post from the other forum was my information as that is my photo edited with a red arrow.
The original Hot feet fix works great. The heater control valve keeps the heat out of the HVAC and allows better cooling during the air conditioning season. The last part of these was the Hot Feet Fix II which stops the flow of air. That is helpful in keeping the interior clean in dusty conditions.

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