Sorry it took me a couple of days to reply. To your questions:

1) I used a flat blade 10 Amp fuse (just because it fits better than the copper wire I had before). In the picture I uploaded you can see the blue head of the fuse to the left of the failed Red sensor.
2) Regarding the fans not working, you can leave the car running on park for a while and check if they operate or not. Unfortunately, my knowledge is limited about the fans affecting the functionality of the compressor.
Something I can assure you is that if the Tachometer does not work the compressor will not work. The most likely cause for it not to work is that the overload relay with the Red fuse on its top is either faulty or loose. Perhaps the connections (legs) need some cleaning. Other possibility is that the wires coming to the connector that meets that relay could also be loose or be dirty. Even if the Tachometer works when you start the car and it fluctuates for a second due to a loose connection, it will kill the compressor and it will only reset if you turn the ignition all the OFF and then back ON.

If your compressor worked on the road, it is likely that there is nothing wrong with it and the bug is in an electrical connection. Once you do the bridging of the pressure sensor you will find out. I am not an expert on this but I hope the info helps.

 

Thanks, I'll try that. My tachometer doesn't have any issues (fluctuations, etc.). Since the MBZ guy told me that the RPM sensor in the compressor was not working, do you have any idea what that signal is like (is it a pulse or a level feedback). One thought I had was to feed the same signal that feeds the tachometer in place of the one in the compressor. Any of you gurus out there are welcome to respond.

 

I bypassed S32 as you suggested. Now my A/C fans work, but I still don't have A/C at low speeds. I guess it must be the RPM sensor in the compressor. I'm hoping to find a way to "fake" it out. Any suggestions would be appreciated!

 

I was trying to upload a procedure that could help you find your car's problem but they are too large to upload to this forum. See if you can find somewhere on the internet MB Procedure 83-605 Testing Compressor Cutoff and remedial measures. Otherwise you can buy the W124 repair manual online for less than $20 (ebay) in html format and all this info is there.

 

The 83-605 advice was a great help. I found it on line and it should really help.

Thanks!

 

See if you can also find 83-604 and 83-601 (called by -604). W124 Performance is a great site maintained by a forum member. The funny thing about all this is that my now A/C began acting up again so I will probably start doing the same testing in parallel. Good luck.

 

Hi again. After testing the wiring and components I got very frustrated because everything tested OK but I realized that by removing the N6 module and bridging connector #5 and #7 of the N6 receiver socket the compressor would work like a charm. So, that is what I did. I bridged them permanently and I get cold air. The Climate controls at the console remain operational so nothing changed on that side. Good luck.