Same car.....another issue......

Have tried on SEVERAL occasions to replace A/C condensor on this car in the front section under the hood (actually my mechanic has tried)....using certified RECONDITIONED parts from various vendors: DELCO (US) as well as GERMAN OEM part. Have been unsuccessful in getting A/C to operate properly or AT ALL after several installations of different condensors over the past three years.....EXPENSIVE to take out old unit and install new unit.....the most time that the A/C has worked is ONE DAY ONLY...and then it craps out......

Any suggestions on what is going on here, or what part WILL WORK or what we are doing wrong on this front? I know that A/C units on these old MBs are notorious for being a real pain, not working, or not able to be fixed properly......some folks have same car and A/C has ALWAYS worked well and others have cars where A/C has NEVER worked well......

Any input would be greatly appreciated.......