A/C Evap sensor

[Mook613]

I had a shop do a R-134 conversion for me with a new condenser.
Ended up working with some cold vent temps, but a leaking compressor necessitated a replacement.

Finally got them to install a rebuilt compressor, but then they tell me that there's no power running to the compressor.
The blue light will turn on, the engine RPM rises, but sadly no compressor power.

After several hours of wire tracing they think that it is the evap temp sensor/regulator.

Is there anything else I should have them check, and does anybody have one of these sensors (they are extremely expensive if I have to order new)?

[jeffnhiscars]

Bypass it with w jumper at the connector until someone sends you used one. All it does cut off the compressor if the sensor hits 37 to,prevent evaporator icing.

[Das Delfin]

the regular is like 35 dollars and easy to replace. It's under the dash on the drivers side up next to the heater box

[Das Delfin]

to follow up, if your blue snowflake light is coming on and your pressure switch is working correctly then the only other parts are the evap temp regulator and the evap temp sensor. The ETR is a 6 pin relay under the dash and isn't expensive. I don't know about the sensor. Typically the relay will go bad due to weak solder joints/heat cycles etc. I had a thread about this but the gyst is you'll get the rpm change and the blue snowflake but you won't get 12v at the compressor.

Later cars had this. I think from 1987 and on. eta cars had a simpler setup. It is worth your while to download the electronic troubleshooting manual for your car and trace the diagram. Search google for "wedophones bmw manual" etc. They can be downloaded from the wedophones website

[Mook613]

to follow up, if your blue snowflake light is coming on and your pressure switch is working correctly then the only other parts are the evap temp regulator and the evap temp sensor. The ETR is a 6 pin relay under the dash and isn't expensive. I don't know about the sensor. Typically the relay will go bad due to weak solder joints/heat cycles etc. I had a thread about this but the gyst is you'll get the rpm change and the blue snowflake but you won't get 12v at the compressor.

Later cars had this. I think from 1987 and on. eta cars had a simpler setup. It is worth your while to download the electronic troubleshooting manual for your car and trace the diagram. Search google for "wedophones bmw manual" etc. They can be downloaded from the wedophones website

Thanks!
I'm having a shop do my A/C work (I do most of the work on the car, but some things I just leave for my local mechanic).
They have traced/tested pretty much everything and all that could be left is the ETR.
As you noted, the pressure switch works, the blue snowflake comes on, and the RPM rises.

The only part number I can find for an ETR is 64511386920. This is about $150USD everywhere that I look.
Is there something I am missing regarding the cost?

Thanks again.

[Das Delfin]

try this one https://www.eeuroparts.com/Parts/108...l-64508390158/

source:

https://www.realoem.com/bmw/enUS/showparts?id=BB13-USA-06-1987-E30-BMW-325i&diagId=64_0525