System Test
- Check that all in-line fuses or circuit breakers are operational and supply power. With control switch turned "ON", measure voltage of Purple wire at rear window grids. There should be approximately 12-13 volts, if not check wiring harness, control switch or relay timer.
- Connect negative lead of voltmeter to ground. At midpoint of grid lines voltage should be approximately six volts. If voltage is 12-13 volts, there is a break between midpoint and ground. If voltage is zero, there is a break between midpoint and input side of grid lines.
- Disconnect switch leads and check that it is switching properly. If switch is operating normally, install a new relay timer and check operation of system. If system now operates normally, replace relay timer.