System Operation: Notes

The heated windshield system will only operate under the following conditions:

• Temperature of passenger compartment less than 50°F (10°C).
• Engine running.
• Battery voltage at least 11 volts.

The heated windshield is turned on by an on/off switch. When this switch is turned to ON position, a timer relay starts a 4-minute timing cycle. Power is then applied to heated windshield control module.

When the control module receives a power signal from the on/off switch, it activates 4 functions:

• Turns on driver indicator light.
• Turns voltage regulator off.
• Energizes alternator output control relay, switching alternator output from vehicle's electrical system to the windshield circuit.
• Restores alternator's output by turning voltage regulator back on.

Battery voltage drops to 12 volts when disconnected from alternator. The voltage regulator will then full field the alternator. Alternator output voltage will then rise to 30-70 volts, depending on engine speed. The control module and voltage regulator limit windshield voltage to 70 volts.

If battery voltage drops below 11 volts, control module will cut off power to alternator output control relay. This action will reconnect alternator to vehicle electrical system. When the 4-minute timing cycle is over, heated windshield is turned off and charging system is returned to normal operation.