Heater control valve

Looking for a working heat control valve for 1987-88 Turbocoupe.  Valve sits near the firewall, in the hose that lets hot water into the heater core, it has a 2-wire connector on top.  Mine is frozen so the heat is stuck on.

I don't know if all Turbocoupes use the same valve, but my car has the Electronic Climate Control with digital temperature setting.

Thanks

Turbo Coupes with manual heat/AC controls do not have any valves in the coolant flow path. Heater output temps are modulated via the blend door which is cable operated.

Turbo Coupes with manual heat/AC controls do not have any valves in the coolant flow path. Heater output  temps are modulated via the blend door which is cable operated.

Thanks but I don't have manual controls.  I have the Electronic Climate Control, which lets me set a temperature.  It has a valve on the heater core coolant line.

Turbo Coupes with manual heat/AC controls do not have any valves in the coolant flow path. Heater output  temps are modulated via the blend door which is cable operated.

Thanks but I don't have manual controls.  I have the Electronic Climate Control, which lets me set a temperature.  It has a valve on the heater core coolant line.

If it's inline to the rubber hose that goes through the firewall for the heater core inside, that's not a valve. It's a 2-wire sensor that the Electronic Climate Control uses to know coolant temperature. Specifically, it will lock-out the system from blowing cold heat if the the temperature is too low. It does not use any electronic valves.

Turbo Coupes with manual heat/AC controls do not have any valves in the coolant flow path. Heater output  temps are modulated via the blend door which is cable operated.

Thanks but I don't have manual controls.  I have the Electronic Climate Control, which lets me set a temperature.  It has a valve on the heater core coolant line.

If it's inline to the rubber hose that goes through the firewall for the heater core inside, that's not a valve. It's a 2-wire sensor that the Electronic Climate Control uses to know coolant temperature. Specifically, it will lock-out the system from blowing cold heat if the the temperature is too low. It does not use any electronic valves.

Here is a picture:.  https://www.flickr.com/photos/[email protected]

If this is only a sensor, then why is it always putting out hot air?  What controls the temperature?  I removed the A/C years ago and it has always worked fine to adjust the heat temperature from 60 to 90 deg.  But In September it started blowing very hot air all the time, now it blows warm (not hot) all the time, no matter what it is set to.

Turbo Coupes with manual heat/AC controls do not have any valves in the coolant flow path. Heater output  temps are modulated via the blend door which is cable operated.

Thanks but I don't have manual controls.  I have the Electronic Climate Control, which lets me set a temperature.  It has a valve on the heater core coolant line.

If it's inline to the rubber hose that goes through the firewall for the heater core inside, that's not a valve. It's a 2-wire sensor that the Electronic Climate Control uses to know coolant temperature. Specifically, it will lock-out the system from blowing cold heat if the the temperature is too low. It does not use any electronic valves.

Here is a picture:.  https://www.flickr.com/photos/[email protected]

If this is only a sensor, then why is it always putting out hot air?  What controls the temperature?  I removed the A/C years ago and it has always worked fine to adjust the heat temperature from 60 to 90 deg.  But In September it started blowing very hot air all the time, now it blows warm (not hot) all the time, no matter what it is set to.

Yeah, that's the cold engine lockout sensor used by the electronic climate control to prevent blowing cold air when the engine is cold by not allowing the fan to turn on until the engine coolant reaches a certain temperature. It is not a valve, it does not block coolant to/from the heater core and does not directly control temperature.

You would need to do some diagnostics because there is 1) An Ambient Temperature Sensor inside the vehicle that is used by the climate control to maintain the set temperature and 2) The door that allows temperature blending and 3) outside factors that also result in temperature output (heater core flow, coolant level, t-stat, etc.,).

There is a diagnostic mode that the control unit can be put into but the tests are limited.

After searching the forum and the internet, I was able to run get the diagnostic test, I got "88" which means no issues.  So I took the blower box apart and I found a mouse nest!  It  was plugging up everything so the heat could not not shutoff.

BTW is anyone is interested, here is how to run the diagnostic:

To initiate the EATC self-test, simultaneously press OFF/AUTO and DEFROST, release and press A/C within 2 seconds.  A code will be displayed.  Push the COOL button to exit the diagnostic. 

Code 88 = no issues
Code 01 =  blend door out of position
Code 02 =  floor/panel door actuator
Code 05 = blend actuator overcurrent (door is stuck or bad actuator motor)
Code 12 =  bad thermistor.