While I had the engine out of the 05 E320 I replaced the a/c compressor and dryer because of the compressor pulley bearing noise issue. I did not purchase the compressor from MB which may be my first mistake? Anyway, did everything right and even vacuumed the system for 24 hours before charging. Now, the compressor does not seem to be working. Pressure on both sides is at a little more than 100 psi with the applicable ambient conditions. I hooked the Autel system up to it and it is indicating the compressor is drawing 2440 mA. The upper range on the Autel is indicated at 750mA. The only climate control fault code is interior temp sensor fault code but I'm pretty sure that was there prior to starting on the car. The a/c system worked fine before I replaced the compressor. My first thought is that the mA load is preventing it from working properly. The auto light stays on on the pushbutton unit and the blower blows like it is supposed to when it is working properly.

Worst case I'll hook SDS up tomorrow and dig in to it a little deeper.

__________________
Jim

did you test the resistance of the clutch magnet coil - wait - umm does this one actually use a compressor clutch?

My W210 compressor clutch fried because of exessive air gap which then caused chattering and eventual overheating of the clutch. - In that case the coil windings were showing open circuit and everything tested good including the voltage test for the compressor clutch wire.

I had to reset the klima control unit in order to get the compressor to run otherwise it gets locked in error.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Unfortunately, this one does not have a conventional compressor clutch. First time I have delt with this type application so I'm on somewhat of a learning curve.

__________________
Jim

It's a variable demand set-up, no clutch and the compressor displacement is controlled by the climate control unit. Don't know if control signal is a pulsed duty cycle deal or a variable current/voltage (or both).

You can monitor the duty cycle percentage request from the ECU using SDS and under actuations you can manually manipulate the compressor settings.

Stupid question but you did remember to plug the electrical connector back into the remanned compressor? You mentioned it wasn't an MB replacement part, where did you get it?

SDS seems to also indicate that 750ma should be the maximum current draw possible, is it possible the compressor you got doesn't know about variable demands?

__________________
98 Dodge-Cummins pickup (123k)
13 GLK250 (135k)
06 E320CDI (323K)
16 C300 (62K)
82 300GD Gelaendewagen (54K)

Thanks Tim.

I got it from Global Parts in Macon where I purchase a lot of a/c parts and the compressor is plugged in. The compressor was made in China. The front pulley arrangement is different than the one that came off.

During the observation yesterday the Autel was indicating that the controller was attempting to run the compressor at 70%. I may just try changing the pulley bearing on the old compressor and put it back in. I got the holding tool ordered.

__________________
Jim

Will the Macon boys upgrade you to a real compressor like a Denso? If I were going to redo this job, I'd want a good quality compresssor so I don't have to redo it for many 10s of thousands of miles. How many miles are on the original?

__________________
Prost!

210k+.

That is about what I have decided to do. I will see if they have the Denso available.

__________________
Jim

Installed it yesterday, vacuumed for 24 hours, charged it as applicable and you can hang meat in that baby now.

__________________
Jim