The ac is intermittent on my 98 ML320 and I think the evap temp sensor is bad. When I can get the compressor to engage it blows ice cold. The freon has been checked and that's OK. Fuse 44 is OK too. I have a new sensor and looked under the dash near the gas pedal on the evap box as instructed by the MB parts guy but I don't see the sensor. Do I need to go up higher through the instrument cluster to get to it?