Get a better experience by installing our free app!
Not now
Install
Get a better experience by installing our web app!
Hide
How to do it?
In Safari, tap on the menu bar. Scroll down the list of options, then tap Add to Home Screen.(If you don’t see Add to Home Screen, you can add it. Scroll down to the bottom of the list, tap Edit Actions, then tap Add to Home Screen.)
Just ran the test on the defroster flaps. I did not hear the flap move, but the resistance went from 2,150 ohms to around 90 ohms. Then back to 2150 ohms. I took a look at what I believe is the servo for the defroster flaps. Is this it? If so, it did not move.
I also noticed this lone connector in the CCU area. Not sure what it is, or what it would connect to.
The compressor is brand new, and I hear/feel it kicking on when I hit the AC button. I am putting off checking the vacuum lines for the heater valve since the valve itself is buried by the firewall. Frankly, I would know what to do to test it anyways.
It's hard to get oriented to that picture but I think you circled the foot well flap servo. See diagram below. Odd that you didn't hear the motor move, yet the position sensor changed? Wonder if it's linkage has a broken clip, although I still think you'd hear it move. I'm not even sure that would create an always-hot situation, but if it's not working, then it would seem to be the leading clue. That connector is probably the cigarette lighter light bulb holder. See link below on that, along with another thread that gets deeper into the cc unit (or at least the version I'm used to seeing).
I indeed mistook the footwell motor for the defroster servo.
I'm scratching my head with this. The servo for the heater control flap is not working when I attempt to control it with the CCU, but I really don't know why when I move the flap manually it wouldn't blow cold. Would a vacuum leak at the heater control valve or anywhere else in the HVAC system cause the CCU to not send the open/close signal to the heater flap servo motor? And if there were a vacuum leak, could that cause the full heat condition despite the manual opening/shutting of the heater control flap?
Could be multiple issues. If all three motors work when you manually power them using the charts (do they?), and if all three temp sensors check out, and if the solenoids click when powered -- then either your heater valve is stuck open or the cc unit is malfunctioning. As for hot air after manually closing the flap, that suggested the heater core is still getting hot coolant and the heat is radiating out into the air stream despite that one flap trying to close it off. I think it's time to check the heater valve. When that valve is not getting vacuum or if the diaphragm is ripped inside, it will default to open/hot. If the heater vale works (shuts off the flow of hot water when it has vacuum), and if its vacuum solenoid clicks when you power it, then most likely the cc unit is malfunctioning.
Tom wrote: Sun Jul 02, 2023 9:43 am
Could be multiple issues. If all three motors work when you manually power them using the charts (do they?), and if all three temp sensors check out, and if the solenoids click when powered -- then either your heater valve is stuck open or the cc unit is malfunctioning. As for hot air after manually closing the flap, that suggested the heater core is still getting hot coolant and the heat is radiating out into the air stream despite that one flap trying to close it off. I think it's time to check the heater valve. When that valve is not getting vacuum or if the diaphragm is ripped inside, it will default to open/hot. If the heater vale works (shuts off the flow of hot water when it has vacuum), and if its vacuum solenoid clicks when you power it, then most likely the cc unit is malfunctioning.
Is there any way to test the vacuum solenoid without the CCU attached? As in, can I give it 12v power and hear them click like you can with the defroster flap and heater flap?
I checked to see if the heater control valve had a vacuum leak. It seems to hold vacuum just fine when hooked up to my hand vacuum pump. That said, I turned the car on and had someone go from full heat to full cool. The valve's arm did not move at all—but, it was in the closed (cool) position. When I shut the car off, the valve went back to the open position.
Oddly enough, I now hear the solenoid constantly clicking from the passenger footwell. I don't remember that happening before I took the CCU apart. Starting to sound like this might be an expensive trip to the shop! Really hoping I didn't damage the CCU unit when I took it apart.
Check the last page for the solenoids. Chances are the cc unit was the problem all along. I can hook it up to my spare heater core unit to test it if you want...
That would be so greatly appreciated! That would give me some confidence before spending $6-800 on a new one for it to not be my issue.
It seems like everything is working separately from the CC unit... but nothing works once the CC unit is telling them what to do. I can't tell you how much I appreciate your generosity with your time and expertise.
TurboD wrote: Sun Jul 02, 2023 7:51 pm
That would be so greatly appreciated! That would give me some confidence before spending $6-800 on a new one for it to not be my issue.
It seems like everything is working separately from the CC unit... but nothing works once the CC unit is telling them what to do. I can't tell you how much I appreciate your generosity with your time and expertise.
Happy to help. If you want me to test it, send me a PM or email me at [email protected]
