heater control valve?

[wade]

hi guys, in the process of removing my evaporator , and the haynes manual as well as the gm shop manual make reference to removing the heater control valve when taking the heater core hoses of the heater core. i have seen the pics in the haynes manual and i dont have this control valve. was this mabe not installed on the electronic controlled units? as far as the shop manual diagrams go, the hot cold selection is entirely dependant upon the opening and closing of
the temp control valve, which is in the housing itself. so why is there a seperate
valve installed just prior to the heater core? and do i need this valve? only funtion of this that i can see is to turn off the flow of coolant to the core.

 

[Ken]

I don't have a clear picture of it, but it is the valve with the vacuum line connected to it, located on the right side of the engine compartment on the inlet (?) side of the heater hoses.

The valve is part of a larger piece that incorporates the two heater lines, both the feed and return.

 

[thirdtimevetteowner]

Ken, It sounds like the heater control valve may be the culprit causing my heater to blow ALL the time. Make sense? Do you know of anyway to test it? My '89 has the Climate Control option, so I don't have a clue as to where to start trouble shooting. Any help, from anyone will be muchly appreciated.

 

[wade]

As far as I can tell the temp. controller is the only thing on my car that controls the hot and cold. I tested the door today and in full cold it bypasses the heater core and full hot bypasses the evaporator. This functions fine on my car and that is why I can't figure out what the heater control valve (that I don't have) is for. And yes it is that control on the right side of the firewall. And "thirdtimer", I would suspect that your temp. controller inside the airbox itself is possibly at fault. If you have an electronic controller without the car running you can hear the door open and close by switching full hot full cold, with the ignition on. (Start car first before you try this, then shut off so you have plenty of vacuum.)

 

[Ken]

Do you know of anyway to test it?

Apply and release vacuum to the valve; it should open and close accordingly.

 

[thirdtimevetteowner]

Thanks guys, I will give it a try today, and keep you posted.

Rich

 

[tigmaned]

my value was leaking coolant the other day, and i tried bypassing the system all together since it summer and all. took both coolant lines off and adapted a fitting for both to run into each other. but i forgot the tiny line coming off the intake?? lost alot of coolant quick, luckly i only took it for a short half mile trip!!! so i stopped hook the coolant lines back up to the heat value put water back in, and the value wasn't leaking anymore?? i manually pushed and pulled it in and out and it seems fine now?? man i was like i almost took out my motor for this dump value and now its fine??

 

[JonM]

Its the thing with the little hose running into the top.

 

[tigmaned]

jonM
your 1984 is diff then our C4's

 

[JonM]

jonM
your 1984 is diff then our C4's

My mother always told me I was different and special...even when she left me at that "school" for the other special kids. :L

 

[tigmaned]

took the short bus?

hey one thing nice about 84's you don't have so many fuel problems as us TPI vettes.