Thermistor on a stick - that's funny! I like it.

Also, it's not normal for the low side lines under the hood to be covered in frost. Dripping condensation, yes, but not turned into a popsicle. The frosting is generally an indication the low side pressure is too low; the most likely cause is an undercharged system. (In refrigeration lower pressure on the low side equates with lower temperatures - that's why you got frost rather than condensation.) Any idea what your high/low side pressures are after a few minutes at 2000RPM? If the high side is reasonable, you may be able to bring the low side up by adding refrigerant.

Your real problem was the evaporator was covered in ice. Insulating the low side lines won't change that behavior. Perhaps you forgot to install the evaporator temperature sensor? I've never seen an MB that did not use an evaporator temperature sensor to cycle the compressor as a control for evap. freezing.

- JimY

Evaporator temp sensor is inplace. I will recheck the charge. MAybe it was undercharged to begin with. This is actually the first drive over 2 hrs. it's done since repair last year. I was wondering why it only took 1-1.5 cans to fill it the first time. I would need to soak the refrigerant can in warm-er water basin... i'll keep you guys posted.

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a2


1978 280 CE silver
1986 560 SL black
1987 300 SDL cream
1994 SL 500 brilliant green
1997 E 300d dessert silver
2005 FORD F250 Superduty Crew cab 4x4

____ADMU____

Whats the best way to gain access to the expansion valve on a 91 300sl...remove brake booster or remove air plenum? Ineed to change my o-rings!Thanks,Dan

you need to remove the air plenum-- you don't have to touch the booster at all. good luck

__________________
a2


1978 280 CE silver
1986 560 SL black
1987 300 SDL cream
1994 SL 500 brilliant green
1997 E 300d dessert silver
2005 FORD F250 Superduty Crew cab 4x4

____ADMU____