I have a 91 300e . The compressor was replaced 2 yrs ago. The car starts coolling perfect in the morning. When i go out to run errands in the afternoon, it takes about 10 minutes to start blowing cool. This just started happening. In the past the car usuallywould blow cold in a couple minutes even after sitting out in the 110 degree AZ sun like my other cars. Is there a temp sensor that mightstop the compressor from engaging, when it is really hot, that might have failed. I took it to Mercedes and they said bad expansion valve $950.00 to fix.I said no thanks. Then i took it to the A/C place andf they said expansion valve is fine. They converted to 134. They said a very small leak in compressor and could go fine for some time. Mercedes said compressor was fine. Same symptoms continued. Sometimes i can turn the car off when blowing warm then turn it back on and is starts to blow cooler. I am stumped. Thanks for any help