AC system leaks and/or a faulty evaporator temperature sensor can cause poor AC cooling. The failed sensor can prevent the AC compressor from coming on. Leaks cause a low refrigerant level, which reduces the ability to cool.Google+
Car Problem Reports
Mercedes-Benz ML430 AC System Leaks/Bad Temperature Sensors May Cause Poor Cooling
Mercedes-Benz ML430 Problem
Average Mileage: 146,857 mi (76,000 mi - 221,000 mi)
Visitor, 2000 Mercedes-Benz ML430, 76,000 mi
I'm experiencing A/C problems very similar to that described in this post. Scheduled to take to the maintenance shop next week to have it checked. Will update upon completion.
my whole hvac system is crap. I'm hot in the summer and freezing in the winter...so sick of the problems I'm having with this car.