P311-308C8FA 1711886 New
- ; A/C Control Head Knobs OE Numbers F3TZ18519A; F65Z18519AB; XL3Z18519AA; YL8Z-18519-AA
- The electrical switch is designed to give feedback to the engine management system. The ECM controls the A/C system on modern vehicles. In earlier vehicles, they are used to directly turn the compressor off to avoid compressor failure.