Keep your Foxbody engine properly cooled with replacement 1979-93 Mustang cooling system sensors. Coolant temperature sensors are a very important part of your cooling system. These sensors relay temperatures back to the computer to determine timing, EGR flow, and air/fuel ratio. Neglecting a faulty sensor can cause major problems to your engine. Temperature sending units relay information to your gauges to let you know how hot/cold your motor is. Not knowing if your engine is overheating can lead to serious damage. Replace damaged or melted wiring harnesses with 5.0 Resto's replacement pigtail connectors. These sensors and pigtails fit 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, and 1993 Fox Body Mustangs.