Ford Parts 7C19-8B607AA AC Evaporator Temperature Sensor for Ford Transit V348 On a Transit V348 / New Gen Quanshun, the 7C19-8B607AA is the little NTC sensor that lives inside the front A/C housing, right at the evaporator outlet. The HVAC module reads it to decide when the evaporator is about to freeze (around 0–4 °C) so it can cycle the compressor clutch, and to hold the temperature you set on the dial. When the probe drifts high, the module thinks the core is still warm