Compressor fails to start

[mooncake]

My 964 was fitted with a 240v motor and an electronic air conditioning kit, using ccu mode

fan test normal，When the voltage is greater than 13v, input cmp=50 and the compressor cannot run

Could this be a problem with the compressor?

[classicretrofit]

Thanks for your post. It is very unlikely to be a compressor fault.

Have a look at this thread for our checklist  as to why a compressor won't always start: 

This is a much more detailed troubleshooting routine for when the checks in the first thread are not successful:

Finally here is some advice on 964/993 CCU specifics albeit the compressor has usually kicked in:

 

[mooncake]

8 minutes ago, classicretrofit said:

谢谢你的帖子。这不太可能是压缩机故障。

请查看此线程以了解我们的清单，以了解压缩机无法始终启动的原因： 

当第一个线程中的检查不成功时，这是一个更详细的故障排除例程：

最后，尽管压缩机通常已启动，但这里有一些关于 964/993 CCU 具体细节的建议：

 

I have tried, the blower is turned on, connected to a 47k resistor, and the voltage is guaranteed to run at 13v+ for more than 1 minute

[classicretrofit]

OK, I have asked Jonny to look at your data and we'll see what he thinks.

[mooncake]

2 hours ago, classicretrofit said:

好的，我已经让乔尼查看了你的数据，我们会看看他怎么想。

When I press the snowflake button it turns into hipower

 

[Jonny Retrofit]

The trace looks ok  (but I did notice that the BUT settings should be Latch for snowflake operation). 

I would look at the heavy current supply on the red cables.  Try a direct connection of the compressor to the battery.

[mooncake]

2024/6/12 下午5点05分，Jonny Retrofit 说：

跟踪器看起来没问题（但我注意到设置了雪花操作的闩锁）。 

我会查看红色电缆上的大电流供应。尝试将压缩机直接连接到电池。

My battery idle voltage is not high, and I have set BLO120. Can I get a better idle voltage by replacing a high-performance battery?

[Jonny Retrofit]

In normal driving conditions the compressor should not switch off.   Try driving the car instead of leaving it to idle.  

[mooncake]

17 hours ago, Jonny Retrofit said:

在正常的驱动条件下，压缩机不应关闭。试着把车开着，而不是让它闲置着。

There's only one problem. I don't think the cooling is strong enough

How do I set a lower temperature？

[Jonny Retrofit]

Set CHI=95

Set CTS=18

Do you have our high output alternator?

[mooncake]

2 minutes ago, Jonny Retrofit said:

Set CHI=95

Set CTS=18

Do you have our high output alternator?

yes 240v high output alternator alreay install

 

[Jonny Retrofit]

Are you sure the compressor is running?  On the computer,  the current (CompI) should show about 75A when running. 

[mooncake]

Just now, Jonny Retrofit said:

Are you sure the compressor is running?  On the computer,  the current (CompI) should show about 75A when running. 

Yes, the compressor is running, but it feels a little cool, but not enough，The fan is also running

[Jonny Retrofit]

We need to see the DIAG trace with the compressor running ( e.g. CompI > 0A. ).   Did you leak test the system?

[mooncake]

On 6/23/2024 at 6:27 AM, Jonny Retrofit said:

We need to see the DIAG trace with the compressor running ( e.g. CompI > 0A. ).   Did you leak test the system?

With no leakage, the idle voltage will be low

[mooncake]

On 6/22/2024 at 3:14 AM, Jonny Retrofit said:

Set CHI=95

Set CTS=18

Do you have our high output alternator?

I tried this setting and the compressor didn't work again

[mooncake]

On 6/23/2024 at 6:27 AM, Jonny Retrofit said:

We need to see the DIAG trace with the compressor running ( e.g. CompI > 0A. ).   Did you leak test the system?

When I set chi=95, the compressor often shuts down. When I set chi=90 cts=16 and keep 1500idle, the following data is obtained. The outlet temperature is about 20, is there any way to keep the outlet temperature around 10 degrees?I added 700 grams of snow,

[Jonny Retrofit]

You need to drive the car.  If you let it idle, the system is designed to slow the compressor to low speed (SPD=001 on your trace) and the cooling will be less.  When you drive, the voltage will pick up and the cooling will be better.

700g is a bit too much refrigerant.  you might get better results with less - say 600g.

[Jonny Retrofit]

Also, are all your servo dampers working properly?  It is very common to have heat flaps stuck open on these cars which will compromise the AC performance.