My son's 1988 VW Scirocco 16V coolant sensor red light comes on, but the gauge does not work. Where do you think it might be bad, gauge, sensor wherever it is, or what. Need help in a hurry for the prom Sat. night. Walter D. Leonard III 1999 VW Passat S/W Colorado Red 1.8 5-speed 1988 VW Fox S/W Alpine White 1.8 4-speed 1987 VW Scirocco 16V Alpine White 5-speed 1981 Kawasaki GPZ 550