Quote:
Originally Posted by jordon001
(Post 3490138)
I have a 96 e300d and started car today and heard a squeal and then it stopped. Driving and noticed no ac. Looked user hood and clutch was not engaging. Read and cleared the codes and now clutch engages, but still blowing hot. Have 2 codes that won't go away:422,459. Both deal with the instrument cluster from what I've read but I need to know what to do and what's wrong. Please help its 100+* here in Florida.
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I just went through this with my 1991 300SL, but it's true for all a/c units for cars. When the car is running, you turn on the a/c, you hear a short squeal, then the car stops running, what has happened is that your a/c clutch engages, but since the compressor is seized (will not move due to some internal breakdown), it causes resistance to the motion of the engine, it is detected and the engine controller shuts down the engine.
With the engine off, reach down with your hand and see if you can turn the only the clutch part clockwise or even at all. I think you will find that, as I did, you will not be able to turn the clutch. If you are able to move it with only moderate resistance, then you are lucky. The squeal is a typical sign that your compressor is locked up and is in need of replacement.
Otherwise, if it can be rotated, unplug the two leads to the pressure switch that are right on top of the dryer/accumulator (not at the side where there are two short wires that lead to a sensor). Start the car, take a paper clip and connect the two leads (jump the leads) and this should engage the clutch. If it doesn't, test to see if you get 12 volts at the leads when you jump the leads.
As I said, I'm going through this right not with my SL. When a compressor seizes, it's likely that metal sludge is now in the system and needs to be removed or the cooling won't be very good and your new compressor will have a very short lifespan.
I'm ordering a new compressor, accumulator/dryer, condenser (because it's almost impossible to adequately clean out the very thin passages in the condenser), expansion valve, and will use a/c system cleaner (in a refillable pressurized can and hose- FREE from Autozone Rental Tools) to thoroughly clean several times the entire a/c system (hoses and the evaporator) before installing, drawing a vacuum over a couple of hours and re-filling the system with, in my case, the original R-12 that it was designed for. It had been converted to R-134, but I'm converting it back so that I get the maximum cooling efficiency it had before. Yes it does sound like a lot of work, but it will fit in one full day or over a weekend.
Good luck and let us know what you found.
AL