2011 VW Jetta 2.5L No A/C
A/c button will not illuminate. A/C module was just replaced by customer with a new vw unit. Both wires to compressor valve tested good. I have a unit I purchased that controls the clutchless compressors. I plugged it into the compressor and was able to get the compressor to work properly. Low side dropped to 50 high side went to 210. Scanner reads 116psi with car running. Power and ground to module good. Tested with a light. Compressor shut off code reads 7 which means blower motor is off. Blower motor functions in all positions correctly. I performed basic settings function with scanner. Did not help. Found a manual way to do basic settings by pressing defrost and a/c button. This did not work either. Thinking maybe a bad new module? Any help or suggestions would be great. Thanks
Check for codes and bidirectional control from the scanner if that works I would verify module and check pins at module with wiggle test. Maybe a Sticking relay for the blower? With vw you never know if the part they gave him was the correct one so I'd verify that as well. More Info would help us guide you in your diag.
No codes in hvac module. With blower on and blowing scanner shows blower is off. Module is correct. Everything works except ac button.
Hey I had a vehicle last year with this problem, check the ambient temp sensor, what does the temp read? Also these rarely had relay problems, a/c pressure switch, make sure it’s reading correctly, and its working as it should be, if your cluster is reading different then your temp reading replace cluster, and check to make sure expansion valve is not clogged
I believe ambient was blank. I got caught up on code 7 and scanner showing blower off when it worked in all positions. Pressure switch read correctly.
Make sure new module is coded/configured correctly Or just try a used one from a similar model.if not check all power and grounds to module according to schematics.
Duane; I'm really curious about this “Unit that controls clutchless compressors. Can you fill me in of where to get one? With Gratitude, Steve Wheeler.
I think I found the tool that the author is talking about( wouldve been nice if he just told us) there is a tool by temp select that actually hooks inline to the solenoid on the compressor and can see the signal, and can also send signal. Heres a link I found to the video. Mt3750 sku#696486 partdeal.com/omega-external… youtube.com/watch?v=FyurWL…
Thanks Elias for you kind response to my inquiry. I don't see any other way to isolate the compressor from the control side of the system. This is yet another tool for my list. Best Regards, Steve