Heater control valve

[jetjock]

I dunno...parts store people are known for their excessive intelligence

I should have just posted a link and the Four Seasons number like I've done in the past. See how the first one has holes on both sides? Just flip it over for mounting and swap the actuator. The inlet/outlet are a bit larger in diameter than stock but the hoses go on. And either change the clamps or don't reef on the stock ones...

 

[3rdgen Guy]

wow this turned into an experiment. thanks for all the info, Im definatly buying a brand new one from the dealer. You guys are pretty crafty, good luck!

 

[Moy]

I was about to say you could buy a new one (ideal) or ziptie the lever in the up position (full open). Only thing that it did for me was take a bit longer for the car to warm up, but there were no other ill consequences in that action. I ran it like that for about 6 months with no problems (after those 6 months I took it off because I was tired of getting heat in warm weather)

 

[aggie08281]

So what's the best solution for not spending 150 bucks?

 

[GrimJack]

The posts by Zumtizzle and Jetjock are the best solution.

 

[OfnaRcR4]

I have mine completely bypassed and its not too freezing in my car.

 

[Turbo Habanero]

Mine is also bypassed without a problem

 

[GrimJack]

I have mine completely bypassed and its not too freezing in my car.

Did you bypass the valve, or the heater core? Bypassing the valve has virtually zero affect on the climate control. Bypassing the heater core, on the other hand, is another story.

 

[OfnaRcR4]

Bypassed the valve. I haven't really seen a difference in heating or AC with the valve bypassed. hmm...

 

[jetjock]

The valve's purpose is obtain maximum performance from the AC system. Bypassing does make a difference. Not one easily felt but metrology doesn't lie.

 

[CyFi6]

The valve's purpose is obtain maximum performance from the AC system. Bypassing does make a difference. Not one easily felt but metrology doesn't lie.

How does it do this when the heater core gets hot even with the valve closed? Why does it even need it if the air is directed around the heater core?

 

[OfnaRcR4]

How does it do this when the heater core gets hot even with the valve closed? Why does it even need it if the air is directed around the heater core?

There might be a little bit leaking past but it shouldn't get really hot with the valve closed iirc. Oh I get that it maximizes efficiency of the AC system, I was just saying for the people who don't want to spend 150 on a new one, bypassing isn't a horrible option. Could also bypass the core for the summer to help your AC if you feel like getting under there I suppose.

 

[mkiiichip]

Did you bypass the valve, or the heater core? Bypassing the valve has virtually zero affect on the climate control. Bypassing the heater core, on the other hand, is another story.

The valve's purpose is obtain maximum performance from the AC system. Bypassing does make a difference. Not one easily felt but metrology doesn't lie.

This is probably a dumb question, but I did look...

When is the valve closed? I can see its controlled by the "a/c air mix control servo motor". I would guess it would be shut in max a/c, but what is actually controlling it? I think toyota tried to explain it in their diagram, I just dont quite get it.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=142

 

[jetjock]

Not sure I follow the question. It is, as you said, controlled by the servo and closed at max cooling (below a setpoint of 66 F) whether the AC clutch is energized or not.

 

[mkiiichip]

So, the potentiometer for the mix door controls it?

 

[jetjock]

No, the sliding contact does. Just like it shows. It's mechanically linked to the pot though.

 

[mkiiichip]

Got it now, thanks.