Im helping out a mate who has en EB1 Ghia. His heater is not hot. He had a bit a look, replaced heater tap and was told, by a AC/ Heater place,that his heater core was blocked. I changed his heater core and guess what...still no good. So i took it upon myself to investigate. It seems his heater tap is not opening all the way (by visually inspecting and comparing to my car).
The black longer vac line goes to the intake tree, and the green one to the heater tap. No codes on CC unit. With key K.O.E.O, the blend door seems to move as you can hear it BUT, going from 16 upwards in 1 degree increments the blend door motor/flap moves ONLY until 22 degrees, then nothing is heard from here to 32????
To me it seems the CC unit is faulty.
Next step for me is to try another one. And also try a Vaccum/solenoid box. The one with the colored hoses going to it on the heater box.

Any one have any opinions?

Funny you meantion this, i was just doing some thread mining. It may be your blend door plastic rod as they are known for breaking

na, i made sure i checked everything before i put the heater box back in. To me it looks like the Tap is not getting enough vaccum......? But saying that, when i manually held the tap by hand, it stillw wasnt warm..


Also to add, car IS getting to normal operating temperature.

with the heater tap, no vacuum = tap open (hot).

so if there is a malfunction in the vac system the tap opens by default and the vents go to screen.. worse case the demister still works..

yeah i kinda figured that, but i was just trying everything possible.
So it seems to narrow down to a problem with the blen door motor flap area... Maybe the CC unit is not telling it to open all the way? Its not giving any fault codes but does that still mean its not faulty...?

If the blend air door isn't working properly it would show up an error code, E2 iirc. I get that, but the door still moves, so i'm not sure what the go is with it. I also have trouble with the car getting warm enough to run the heater properly atm, i think the thermostat is playing up, staying open. If the car sits & idles, it will get warm enough & the heater works pretty good considering the e2 error, but if your driving, the car is cools down & the heater stops working.

What's the thermostat like in the car in question, does it work ok? Engine get to normal temp & stay there?

Cheers

ToranaGuy