Alternator Low Voltage Sensor
From Ron Francis Wiring
The popularity of the one wire alternator is certainly well known. Manufacturers are doing all they can to supply the high amperage needs to todays average street rodder. The "ONE WIRE" circuits has eliminated the wiring normally used to control other vehicle functions like the "idiot" light on the dash. The "warning" light is far more visible and attracts your attention much faster then a gauge where the reading / needle may be slowly dropping.
Warning lights provide a quick indication that something has reached the danger point and your electrical system is near the point where a fuel injection engine is about to misfire, a cooling fan will begin to overheat and fail or any electronic circuits is about to shut down. [ Most electronic circuits need about 10 volts to operate.
This product is a voltage sensor that is used with any alternator to light an indicator (idiot) light when the vehicle voltage drops below 11 volts. They can be used in conjunction with a voltmeter, ammeter or by themselves.
This is a simple hookup of a key 12 volt source, a ground and a lamp. You can use an LED, small indicator like those sold by RFW or an existing factory idiot light like those use in most original factory classics.