Heater valve will not close all the way.

[Dragos80]

I got an issue with my TLC 80 series. I searched the forum for my problem but I only found problems regarding no hot air coming in.

The heater valve will not close all the way, so no hot air would enter the cabin. I think this is the issue anyway.
The temperature control slider does nothing between the lowest setting and about 85F.
There is no apparent movement until the slider passes 85F setting, then is opens all the way (the cable retracts and the arm goes down).
There is some kind of short circuit (I think) when sliding the lever between 65F and 85F. It affects the fan speed for some reason. In the video the weird thing about fan speed and temp slider is toward the end. I just can't explain it.

Do you guys have any idea what this is? Could it be easily fixed? Should I sell my left kidney and go to the dealer?

 

[ppc]

Was your engine warm or cold? I would have to assume warm based on your comments. There would be no reason the heater valve would open unless the setting exceeded the "ambient" temperature and heat was required. You stated the the outside temp was about 80. If the engine was warm the temperature sensor in the bumper is going to read high without any air movement. So that all seems to be working properly. You did notice the first time you moved the setting to 85 the system switched from recirculate to fresh. The auto system is going to be a feedback system that normally would make small changes to the heat valve as well as starting and stopping the AC compressor and changing the position of the blend door. The fact the engine was not running and you constantly were moving the slider to the extremes the auto system was confused and therefore the fan speed was changed as part of the feedback system trying to make the proper adjustment. I don't see that you have demonstrated any problem. If auto is switched off then the feedback system would not come into play and would behave more like you have eluded to in your video where the heater valve would open part way.

 

[Dragos80]

The engine was hot.

I had my left hand outside just to compare (while driving) the temp with what was coming in through the vents. I don't care much about steering as I got an ARB bumper out front
The AUTO was off as indicated by the yellow light, it turns green when it is on (the A/C turns on too).
With my other cars, when I turn the temp control all the way down I get the outside ambient temp through the vents. It may take a couple of minutes to get there due to the car being hot, but it gets there.
The LC did not go down in temp after driving for a while, or after being parked on my driveway.

I'll go there again to check it out as it's been dark here for a while.

On FB some said something else about it:

"There is a small white square plug that goes in the back, mine was unplugged when I bought my 450. It was doing the exact same thing"


I'm not sure where that "white square plug" is located.

 

[Dragos80]

Meanwhile I had a beer and that cleared my mind a bit.

If I go outside now and replicate the experiment it will automatically fail, as the engine has cooled off. Therefore whatever comes through the vents will probably be cooler temp. I have to drive it to get it up to the engine's operating temp and then see if the same thing happens.

 

[ppc]

Keep the engine running for your testing.

 

[Dragos80]

Right. Otherwise it would be a false negative result.

 

[blkprj80]

Cracked solder on the slider.

 

[Dragos80]

Someone else suggested the cabin air temp sensor is probably unplugged.
Either way I think I need to take it out.
I still can't explain why the valve does not work in between open and close. It is either shut off or all the way open.