A/C is cold only while driving.

**Briank** · 06-15-2012, 05:56

Originally Posted by PostVW

Think I have the same problem on my NSX, there is no cool air coming at all.
I had the tightness of the system tested and all was OK, they pumped vacuum and then filled with new gas (r134 -it´s a converted system). The compressor is working but there is a stop somewhere in the pipings, they told me that the Expansion Valve is a common problem-part on most car models.
Read about the time-wasting job with the dash and also have the same question:
Can you do replacement of the Expansion valve from the front dept without stripping the dash?

Here is the part:
http://www.ebay.com/itm/New-Expansio...item1e6bc22f23

If there is a blockage in the system who ever serviced it should have been able to tell by the system pressures. I have never heard of a bad expansion valve. Are you sure the compressor clutch is kicking in?

**pbassjo** · 06-16-2012, 12:51

Have you performed the Climate Control Unit's self diagnostic test?
It's on page 22-12 and 22-13 of the service manual found on this site in the Wiki.
This is a good place to start if you want to diagnose your vehicle's a/c problem.
This section of the manual has some other tests and flow sheets that will also help you to narrow down the possibilities.
If you properly diagnose your car's problem you won't be replacing parts you don't need and you won't repair that which is not broken.

**PostVW** · 06-18-2012, 04:25

Yes, it´s a good idea to run the CCU-tests, they can give some good information.
Thanks

**PostVW** · 06-20-2012, 00:18

I have tried to run the Climate Control Unit's self diagnostic test on page 22-12 in the Service manual but having some problem to understand what they mean:
The manual say "To run it, turn the ignition switch ON and turn the FAN switch to AUTO position. Wait for at least one minute on each TEMP display 18 C (64 F), 32 C (90 F). Then, push both the AUTO and OFF buttons ...and so on...
As I understand the ignition shall be ON but the engine not running?
But what do they mean with "wait at least one minute on each TEMP display, shall I start with one minute waiting on 18 C(64 F) and then move every temp-step and wait for one minute at them all the way to 32 C (90 F)? Many steps and many minutes before I can push AUTO and OFF button!

**Briank** · 06-20-2012, 05:08

Run on minimum temp for 1 minute and max temp for 1 minute.

**pbassjo** · 06-20-2012, 08:37

Originally Posted by PostVW

Many steps and many minutes before I can push AUTO and OFF button!

Sheeze.

**PostVW** · 06-20-2012, 22:10

Now I have done the CCU-tests and it was no errors so the CCU thinks everything´s fine but there is still no cold air?
Anyone having some more ideas?

**ysoslow** · 06-20-2012, 22:56

my issue were solved simply by switching out the ground wires. The top one on the engine was corroded, but I went ahead and switched out all of them.

**PostVW** · 06-21-2012, 00:45

ysoslow, which groundwires do you mean?

**sers** · 06-21-2012, 04:49

Originally Posted by ysoslow

my issue were solved simply by switching out the ground wires. The top one on the engine was corroded, but I went ahead and switched out all of them.

I'm also experiencing the same issue. Blows cold when driving on the highway, but struggles to stay cool in stop and go traffic.

Ysoslow, are you saying your problem was solved by changing the ground wires? Do you know how this solved the problem? Which wires exactly are you referring to?

**Briank** · 06-21-2012, 06:41

Originally Posted by PostVW

Now I have done the CCU-tests and it was no errors so the CCU thinks everything´s fine but there is still no cold air?
Anyone having some more ideas?

Have you confirmed the system has a proper Freon charge?

**ysoslow** · 06-21-2012, 07:37

Originally Posted by sers

I'm also experiencing the same issue. Blows cold when driving on the highway, but struggles to stay cool in stop and go traffic.

Ysoslow, are you saying your problem was solved by changing the ground wires? Do you know how this solved the problem? Which wires exactly are you referring to?

my car at idling was pushing out only 12.5 and with a/c on, it dropped down to 11.8. as I rev up the rmp, the number goes up. I figured it was either the alternator or grounds. I went with the cheaper route first and it solved my issue. I changed out all of my grounds. After changing it out, my votage is back to normal on idle. With A/C and radio, it still doesn't drop below 13.